Still waiting on parts for the other two projects so I'm back on the little things with the Camaro.

Since water pump, alternator and starter rebuilding tutorials have been covered many times before, I didn’t take too many pictures of the process, just a few doc photos. So, I won’t bore you with those, but I thought I would share with you the process of my attempt to rebuild/restore the A.I.R, (Smog) pump.

One of the plans for this build that I haven’t divulged yet is to remove the CCC, (Computer Command Control), system and build it to old-school specs, i.e., non-emissions carburetor, mechanical/vacuum advance distributor, no working emission controls, etc. However, I will still keep all the emission parts, wiring harnesses, etc., to keep everything original looking. That said, the pump will be “de-vaned”. A little side story: About 30 years ago I went through a large water puddle and upon startup the next morning I found that the pump had rusted solid. I cut the belt and went on my way. The pump is basically trashed so I don’t see a problem in gutting it.

The first problem I encountered was the lack of documentation on how to service these pumps. There is nothing in the service manual. I could only find one article online about the 60’s and 70’s models. It looked very similar, so I printed it in case I could use it. (It wound up being pretty much identical).

I was a little worried about everything being so corroded. I couldn’t be sure if a stubborn part was because of the corrosion or if I was doing something incorrectly. This was just some of the crud that was coming out of the outlet port.

 

The first task was how to dislodge the fan, (GM calls it a filter), from the hub after I removed the pulley. The service manual says the fan is next to impossible to remove without destroying it. Since the pump was frozen, I was able to simply twist it off with a little persuasion. Next was the rear cap. Using a brass drift, I tapped at parts of the cap that stuck out past the body until it cleared the body. More twisting got the main shaft clear of the vane pivot bearings.


More tapping and twisting got the main cylinder that contained the vanes out of the body.


The front bearing has grooves around the circumference for plastic injection to secure it in the bore. The two injection ports are at the front of the main body. To press out the bearing, I supported the body close to the OD of the bearing with a socket. In hindsight, I should have applied heat to the injection area to soften the plastic. It required a fair amount of pressure to press out. Luckily, nothing was damaged.

 

Removing the rear bearing looked like it was going to be an issue. There was nothing to push or brace against to pull it with a standard 3-jaw puller. I didn’t have anything for my slide hammer to engage the back of the bearing, so I just cut off the end of the cylinder that contained the bearing and end cap. I will simply reweld it back on. Notice how every third roller is not present in the bearing design. The new bearing won’t have this design. Hopefully, it will fit too.

 

After removing the vane seals in the cylinder and pressing out the rear bearing, disassembly is now complete. A session in the bead blaster got everything cleaned up. I found some new bearings. The article I printed suggests the NTN-6203LLBC3/EM for the front bearing. I used a 6203-2RSC3 6203-2RS the front and an SCE248 for the rear. Interestingly, the front bearing is the same, dimensionally, as the alternator front bearing. The difference is the pump’s bearing injection grooves. Just in case the interference fit isn’t enough without the plastic, I’ll apply some epoxy before it’s pressed in. Maybe I can figure out a way to inject the epoxy.



Just to keep things from corroding again, I will coat all the internals with epoxy primer.

 

I got the replacement bearings in and started on those. I guess I got lucky as the bearings are a perfect fit. I pressed in the rear bearing into the cylinder cap that I previously cut off. There is no shoulder for the bearing to ride on, so I centered it in the bore. I noticed that since the bearing is very thin, it didn’t self-align completely. It was cocked a little. I simply pressed a little more on the sides that needed attention and checked it with a caliper.




Next was the front bearing. I did a test press and while it wasn’t as tight as when I removed it I felt comfortable enough with the fit. I scuffed the OD of the bearing race and added a thin film of JB Weld to it and the housing bore for good measure.


As soon as the starter capacitor I ordered comes in for my “no-start” disc sander, I’ll put a chamfer on the cylinder halves and weld it. I got a little ahead of myself with the bearing install. I still need to epoxy primer the interior. No biggie.

 

Time for assembly! I welded the end cap on the cylinder and shot some epoxy on the interior areas.






I then pressed in the cylinder and the pulley/fan hub next.


The finished product:

I wasn’t certain of the correct finishes. I’m sure the aluminum was bare and the pulley was gloss black. I have seen only one photo of an original pump and the rear plate was black, so I went with gloss on that too.






Since I don’t need to be concerned with an air-tight system, I cleaned up the gasket with lacquer thinner and reinstalled it.

 

Another sub-assembly I did a few weeks back were the exhaust manifolds. Before cleaning, I had to remove the driver’s side heat shield. I drilled out the spot welds and then chiseled them apart. I then bead blasted everything.




The manifolds received a few coats of VHT Flameproof Cast Iron and the shields, Flat Aluminum. To get the full temperature rating, the paint has to be baked without your wife finding out. 😉

250 degrees for 30 minutes, cool for 30. 400 degrees for 30 minutes, cool for 30. Finally, 600 degrees for 30 minutes. Our oven only goes to 550 degrees. I shot the heat riser with Satin Clear and only went to 400 degrees. I saw no reason to crank up the heat for the 2,000 degree protection.

I removed the paint in the spot weld areas and plug welded them, just like body sheet metal. A little paint over those areas and I was done. Note the original O2 sensor.

 

Nice work on the AIR. pump!! Can you share the online link for the rebuild instructions? We have a '68 Cadillac Calais that I'd like to 'de-vane'. It still spins, but you never know, and on the '68. engine, the belt also powers other stuff.

Scott Mueller (of 'how to upgrade your PC' fame) did a bunch of mods on the late model B-body Impalas. One mod he did was to pull the heat shields off the factory exhaust manifolds and send them out for extrude honing. He said he got similar flows to what shorty headers had, but the car remained stock-looking. I got a set to do on our '95 SS, but only got as far as getting the heat shields off. They're peened to the manifold with some threaded nails I could not locate. Guess I could have just threaded the holes, but I didn't. Too bad you didn't do that when you had everything apart.... not that it would add much to a 305's performance profile!

 

Here ya go...
https://www.motortrend.com/how-to/15...r-gm-smog-pump
I also just found this too. It's similar.
http://www.camaros.org/forum/index.php?topic=19138.0
I think I have heard of that procedure for the exhaust manifolds. It would interesting to see what any hp increase it might be.

 

They are called drive nails. They aren't threaded but some sort of grooving maybe. You get new ones and beat them into the holes. It's what they use to put metal plagues onto old electric motors and old timey machines that didn't have the plague screwed on.

 

Well you did a great job on the air pump. It looks brand new. Reading your post got me thinking and searching my storage shelves. Found mine, was taken off car when it had about 2 hundred miles on it as part of complete De-smog.

 

Excellent. Thank you so much!

I guess I'm close enough! Now, I just need to find, or make, that stamp. I didn't see that during my photo documentation. I'll look again on the 84 air pump I have. I'll see what bolt heads have on them too.

It's interesting that the date codes are so different. Mine is 3124 and yours is 116. The pulley numbers are different too. Mine is 14037738 and BA GM. Yours is 14087007 and CAY GM. I would expect a little more continuity between the two. I need to look for a code on the other side of the pulley like yours has.

This is off your 83, correct?

I've always assumed my pump is original but with all the times I had it in the shop for the hot soak issues, I wouldn't be surprise if they changed it out. I know they changed out the carb.

 

Yes, that is off 1983. That is interesting about part numbers, but not only different plants the cars came from but i think bean counters made them use whatever was on the shelf It was late in the car year. Think the cut off for new orders was around June.

 

Thanks. Well, the honing gave it the flow of shorty headers, so not anywhere near long-tubes, but better than OEM, and it looked OEM. Those, bolted to export pipes (header pipes that replaced the cats for cars built for the Middle East countries) freed up some HP.

 

I meant to post this a few weeks ago...

I need to keep busy, doing anything to keep this project moving forward. I started on the engine assembly, (Still waiting on parts for those two cars in the shop…) It’s been pretty straight forward, being a stock build. The only thing I upgraded was the camshaft, a Comp Cams # 12-249-4. It has just a little more lift and duration than the factory L69. I don’t want to go overboard on this. I still need to be mindful of the T-5 and rear axle. I also went with hypereutectic pistons. He also balanced the rotating assembly.

In all my years of amateur engine building, (I have built, maybe, 30 engines?), I used Plastigauge to check bearing clearances. For a long time, all I had for a precision measuring device was a dial and digital caliper. A while back, I picked up a set of Chinesium “Insize” brand micrometers. They seem pretty good. I compared them to the other calipers and by using the calibration gauges.

Since I now had the micrometers, I figured I would step it up a notch and get a bore gauge. The prices/quality ranged from maybe $60 all the way up to a couple thousand dollars. I chose the gauge Summit Racing sells. It’s a $200 setup but seems to have a decent reputation. This gauge is accurate down to .0001” where some are only are good to .0005”.

I spent quite awhile to get the hang of things and practice my technique. Of course, I watched many videos too. All the clearances checked out.

Next, was checking the ring gaps. The typical ring gap factor is .004 x bore size for a street engine. So, .004 x 3.756” would give me a .015” gap. However, the Silv-O-Lite Piston instructions say to add 40% more gap for hypereutectic pistons. That puts the gap at .021”. I read somewhere that this type of piston exposes the top ring to more heat. The top ring on the new piston is the same distance from the top of the piston as the factory piston is. So, I am not sure why it would be hotter, but I followed their instructions regardless.

All of the top and second rings in every bore was measuring .015” to .016” straight from the box. For decades, the second ring gap has always been recommended to be smaller than the top because it doesn’t see the amount of heat the top ring experiences. In the last several years ring gap recommendations for the second ring have evolved to be wider than the top ring because it lets trapped gasses & pressure out and helps to prevent top “ring flutter”. Everything I read says this would be for performance and race engines. Silv-O-Lite says the second ring gap can remain at the factory specs. I decided to split the difference and set them around .018”-.020”. I’m not going to over-analyze this; this is a bone stock engine. I used a standard manual-cranked ring filer.

 

Wow, it’s been a long time since I last posted! Too long. There always seems to be something getting in the way of progress. I still have those two other projects in the shop, taking up room and time. Waiting on parts again.

But, I was able to assemble the engine. It’s about 95% complete. I found a set of gray plug wires to replace the black ones I just installed. I am quite certain that’s color they were originally. I could have sworn they were 7mm too, although research seems to suggest it wasn’t until the mid to late 80’s when they started using that size. (I don’t why I didn’t keep the originals). I still need to find a black distributor cap. I might just paint it.

I also found some GM plug wire retainers that are close to the original style. They don’t have the lanyard. I might see about using a plastic insert, like what is used on plastic body panels, to help keep them from coming off the metal stands. The ones I found for the driver’s side that attach to the metal rods are actually better than the originals. They have latch-type design to hold them in place.

I am working on getting the vacuum lines fabbed, cut and bent to match the originals. I found some nylon tubing from McMaster-Carr that seems to be a dead ringer. It’s rated at a max temperature of 225 degrees and seems to have the same stiffness. The part # is 5173K58 if anyone is interested. I did a quick test bend with a lighter and it looks like it will form easily without kinking. I’ll use a heat gun for the final product.

More recently, I disassembled my old rotisserie and sandblasted it. It’s been 20 years since I built it and it has seen better days. I designed the internal balancing mechanism, (sort of like a reverse trailer jack), using regular all-thread. I purchased some Acme all-thread this time around. It should make the jacking/balancing process even easier. I still need to fab the adapters to bolt to the front and rear bumper mounts and then paint it.

The car has sat unattended otherwise all this time. My plan was to pressure wash it first then remove the paint. To get things moving I started stripping the paint first. I’ll just have to deal with the flash rust later. I decided to go with the Harbor Freight paint stripper tool.

Even at full speed it didn’t gouge the metal much at all, nothing a DA with 80 grit can’t handle.


The quarter to roof seam is a much more refined design than the first and second gen cars. It’s interesting how I can easily feel the transition, but I could never see it in the paint.


After I started stripping the driver’s quarter, I began to see the damage repair from when I was hit. It’s pretty much like I remembered, just a couple of shallow dents. I will see if I can hammer and dolly those out a little better. They just filled them in.


I also noticed this years ago: The quarter’s flares where they transition into the upper panels have different contours.





I always thought it was just how the driver’s side turned out after the body work. Both my car and the photos above from another 84 are identical.

For the hood, which is SMC, I stuck with the DA only. I did a little research on the best way to strip fiberglass and saw a mention of paint stripper being absorbed into the substrate, so I nixed that idea. It sounds like if it had a gel coat, there wouldn’t be a problem. There were a few bare areas where the fibers were actually fraying and disintegrating. I’m sure those areas will be low after I sand all the loose fibers off. I’m a fan of Feather-Fill since my body work isn’t perfect. I will apply a few coats directly to the hood and block away.

 

Great thread. Amazing how they'd just let you buy a vehicle with AC back then. lol I may one day get around to putting together my 83 no-AC L69

 

Fill us in on your progress!

 

[QUOTE=69-er;

But, I was able to assemble the engine. It’s about 95% complete. I found a set of gray plug wires to replace the black ones I just installed. I am quite certain that’s color they were originally. I could have sworn they were 7mm too, although research seems to suggest it wasn’t until the mid to late 80’s when they started using that size. (I don’t why I didn’t keep the originals). I still need to find a black distributor cap. I might just paint it.

Could Have Been 8MM These Are My Factory Wires

 

Hmmmm, and they're black! I best start doing some more research. I guess there's always a chance they changed in 84.

I still have some of the original retainers. I might be able to somewhat gauge the size by how the wires fit in the slots.

 

Please post some pictures of the hood prep when done if you don't mind. I have the SMC hood and that is the last item I have to major prep work on my paint job. I want to see/hear on how that prep work goes for you. I bought some SMC filler for my low places and watched some youtube videos on the process but always willing to hear from the more experience folks before I start screwing up parts.

 

I never heard of SMC filler. I might not need any filler because I believe the hood is flat. I'll find out once I start the initial blocking to see where the low and high spots are.

If I do wind up needing filler it would be in the bare areas of fiberglass that was fraying. I would imagine those areas are now low due to the sanding required to remove the loose fibers.









Here's where I am at the moment. I removed the scoop decals years ago when they started peeling and painted them. I'm hoping the underside is still in decent condition so all I have to do is clean and buff the paint. I don't want to have to sand that! If paint can't be brought back, I'll just carefully blast it. 95% is covered by the insulation so all I really need to worry about is the edges.


One thing I need to address is how the hood started to change its curve, relative the fenders. It flattened out for some reason. That will not be an easy fix, whether it's the hood or the fenders that are modified. I don't see me being able to recurve the hood.

 

Thanks for posting these pics! It will give me a guideline on how "deep" I should go with my paint prep on the hood.
I have some for lack of a better wording "missing" gel coat where the paint has lifted off.
I purchased this stuff:
I was going to going these low places first (after sanding the low spots for before applying the stuff above) and then sand the entire hood.
Just to confirm you started with 80 grit on the DA?

 

I've been doing a little research on SMC repair and it seems that an epoxy-based filler needs to be used on SMC. That contradicts what Feather-Fill says. It says it can be sprayed directly to SMC, and it's a poly-based filler. One guy on a body shop forum says he always shoots a coat of epoxy primer before applying any other coating. I've also seen it mentioned that the mold release components are mixed throughout the SMC, unlike fiberglass, and that's why the first coat of anything must be correct.

I've always applied body filler directly to metal, then applied epoxy primer to the filler and the rest of the bare metal. I did a quick experiment years ago. I applied filler over 80 grit sanded bare metal and 80 grit sanded epoxy primer and it seemed the filler had better adhesion over the bare metal. I didn't try different grits nor try applying the filler over non-cured epoxy. I would never be able to finish my filler body work within the curing window of epoxy anyway.

So, right now, I will look into shooting epoxy primer before applying the feather-Fill. I'll shoot the Feather-Fill within the recoat window for maximum adhesion. And, if I do that, I should be able to apply typical body filler over that if there are any low spots.

At least that''s my theory...

And, yes, I used 80 grit with the DA. I'll be using long boards with 80 grit so that will actually result in a bit of a courser finish that what you would get with an 80 grit on a DA.

 

[QUOTE=gt4373;6567593]I guess I struck out. I found the photos of the first refresh back in the 90's. A close up reveals gray wires but they don't have the same printing as yours. I must have changed them out earlier.

 

Switching gears a little bit...

I've been researching the dash restorations from "Just Dashes". It will be $1500 to $1800. I asked Jason about what constitutes an $1800 repair. He said if the basic structure is damaged/broken then the cost will be on the high side. Mine is still in perfect condition so I'm hoping closer to $1500. We'll see. They can charge $1800 all day just because I agreed to the quote. I can imagine what the cost would be for full size padded dash like a 70's Cutlass.





The ribbing on the rear of their pad looks to have 2 as mine has three. Also, the speaker holes are round and not elongated. I've determined I can live with that. I know the texture won't be exact but that's asking a lot. Heck, I know for a fact that the 82 pad that I swapped with mine had a noticeable difference. I did that because even after 2-3 years mine already started to crack. The 82 was perfect. (It didn't last long).

The 82 had a little finer grain than my 83. The side defrost ducts are different too. One has six angled pins that gripped the edges of the hole. The other had tabs. I can't remember which one. I Think the 82 had the pins because to me, it seemed like the tabs were a better/later design. Mine has the pins. Maybe that's because the tab design didn't work with the 82 pad. I wound up having to silicone them in place anyway because the pins broke off easily. I am anticipating I'll be gluing in the ducts on the new one too.

So, I'm not gonna sweat the little things. You can't.

The lead time is at 4 months so I need to get it in the mail now.

 

Those defrost ducts are kind of an interference fit on both our Firebird (~85-86) race car and '92 B4C. Are you sure you need to glue them in?

 

Since the pins are gone there's nothing to hold them in. That's why I glued them in years ago. (And they've held up!) I am going to assume they won't get the shape of the holes exact for a good fit even with new vents. I notice that most of the repros appear to have the tabs. One vendor doesn't show it. It's hard to tell without an image of the backside.

But, I will try to see if the new ones will snap into place before resorting to gluing.

 

Just a quick note on recovering the shifter ball.

My original ball's leather wore out after a few years of use. I eventually got a new one, which also wore out. One thing about the repro ***** is that the stitching is horizontal and not vertical like the factory stitched them. I am always trying to keep the car original when possible, so I decided to find someone to recover it.

Custom-steering-wheels.com said they could take care of me. It turned OK. It took about 2 months. The stitching is a little irregular and not the factory style “baseball” stitching. I’m sure it’s very difficult to stretch the leather so it wound up with a fair amount of wrinkles, a little more than the pictures show in the repro catalogs. And, it was a few bucks cheaper to recover it.

So, which one would I go with if I did it again? It’s six of one, half a dozen of the other. Hopefully, it wears better than the previous ***** did...

 

Major milestone! With the rotisserie finally refurbished, painted, and assembled I was able to mount the car on it and see what I am up against. It’s still not too bad. I’m seeing surface rust in spots. The worst is at a pinch weld behind the passenger wheel well that’s oozing rust from within its layers and your typical hard-as-rock grease and dirt mixture in the tunnel surrounding the rear end pinion seal. It’s about the same around the engine and transmission too. Once I pressure wash it and remove the gunk, I’ll be able to decide what’s next.

I really don’t think I am going to make my early November deadline to paint. Things like this always seem doable, but wind up taking twice as long as planned. I think a spring paint job is more realistic. We wanted the car to be completed by our 40th anniversary in May so I think we’ll just have to celebrate the finished product during our anniversary year instead.

Now I feel like I can start getting things done. One of the other projects is gone so now I have my other bay free to breathe.

 

There were times i wish i had a rotisserie. it will sure make things a lot easier.

 

It's definitely worth the effort in building one or buying it.

 

The rotisserie looks good. A great tool to have for sure.

 

I feel like I am accomplishing something for a change...

It hasn't been this clean since it was new. I scraped most of the gunk off the belly and I'll start brushing on some solvent to get the rest. No new damage to report. It looks like the belly was painted black, (primer maybe?), before the blue was applied based on the overspray. The firewall might have been done the same way too.

I'm trying not to go overboard with this project. The belly and other hard to see areas don't have to be perfect but I think I want to do a light blasting on the belly to clean any hard to get areas. I need to blast the rusted areas anyway. Once all rust repairs have been done, I can then shoot a couple coats of black epoxy primer, then reapply the seam sealer. Much of it is loose and wasn't applied very well. A little sloppy by hand. I will also reapply the wheel well undercoating.

Even though there was factory overspray on the belly, we'll see if I can avoid the temptation to completely mask off the belly before shooting the color.

 

These are the original wires from 1986 on a V6. They look similar to yours but are 7mm. Also notice that each wire is labeled with the cylinder number.

 

I think that jives with what I have been reading that the wires went to 7mm in the mid 80's.

 

Today is blasting day. There are enough scratches, pitting, rust spots etc., on the belly that I am doing a little more thorough stripping of the paint. It will just need to be blasted to metal where there are rust spots and other paint damage. The rest will be dusted to provide some tooth for the epoxy primer. The engine bay paint won’t clean up satisfactorily enough to look nice either. With the rust in that pinch weld and also at a seam on the firewall, it makes sense to take it all down to bare metal. I just hope I can shoot it well enough without tiger stripes and excessive orange peel. I definitely don’t feel like wet sanding all those irregular surfaces.

I spent the morning blasting the engine bay, door jambs, the windshield pinch welds and dusted a few other areas. I’ll be repairing that pinch weld seam after all as there is some rust-through.

We'll see how far I get tomorrow morning.

 

Yesterday, I attempted to chase down loose items rattling and tumbling around that I would hear when rotating the body on the rotisserie. I pinned down the K member mounting caged nuts causing some of the racket. After inserting bolts in those there were still noises I couldn’t pin down. Compared to a First and Second Gen F-body there are really no compartments that can’t be accessed through a hole or other opening of some sort. (Except the frame rails. They have a few access holes. Blowing air into them hasen't produced anything yet). That left the rockers. Unfortunately, there are no holes to access them. I decided to drill a 1½” hole in each of them. This is what I found:

 

I did a little more blasting but the weather isn’t cooperating at the moment. I have returned my attention to the rear bumper cover. I didn’t like the idea of using stripper on the urethane plastic so I DA'd it all off with 80g and finished hand sanding with 320g. I have a few areas that were damaged, the worst are cracks from what appears to be from a hit of some sort. The cracks don’t appear to be all the way through the plastic.

I am trying to find the proper filler/adhesive/epoxy to fill in these areas. I went to my old standby, “autobody101.com” for some guidance. Waiting on an answer at the moment.

Does anybody have experience on repairing the bumper covers?

 

I've had good luck with 3m Polyester Glaze for 25 years.

 

Do you mean the stuff: 3M Platinum Glaze - P/N 05862?

https://store.alloycoatingsupply.com...ge-7000120075/

 

Nope. Unfortunately it would seem they don't offer it anymore. I can't even find an old stock photo of it.

 

For the most part, blasting is done on the body shell. Until I physically get my hands on the actual t-top channels I’ll be using, I’ll be blasting those areas after the old ones have been removed. I need to do some minor blasting on the doors, fenders, etc., as required. I’ll do those items later; I want to get started on the bodywork! One thing I noticed was that it seems easier to remove the sand from the nooks and crannies compared to the other First Gen cars I’ve done in the past. I did just one session so far with the leaf blower and when I rotate the body on the rotisserie, I only get a few grains falling onto the floor.

 

Back to to the bumpers: after doing some research, I decided to go with Polyvance’s “Flex Fill 2” to repair the bumper covers. Soon as that comes in I’ll see how that goes on the rear bumper. I also got their welding rod for any major tears or cracks. So far, I haven’t seen anything that major.






One major repair I’d like to attempt is to level out the caved in areas at the top of the front bumper cover. The areas are recessed by more than ¼”. Polyvance says 1/8” is the limit on the thickness to apply the Flex Fill.

Polyurethane can’t be melted and formed as it’s a thermoset plastic. One thought is to see what heating the plastic does, without trying to melt it, to see if it will soften enough to allow me to push up to level it as possible and them skim with the filler. It seems like it was heat that caused it to collapse to begin with. I’d also like to explore options on how to maybe reinforce the underside to keep its shape. I thought I saw a post or two on this issue, but I have yet find them.

 

I spent a couple hours repairing the rusted out seam in the rear of the right fender well/firewall area. I cut out all three layers of metal as they were all affected by rust through. I modified the repair slightly, going from the factory spot welds to butt welding the patch in and combining all three edges into one patch. Besides the t-top channels this is the only rust repair I will have to do.





I also started the bodywork. This should a piece of cake, at least compared to my past projects. They have all been rust buckets to some extent. In addition to the little dings here and there I am finding very slight low spots when I long block the bare metal panels. I figure I’ll take care of them too. Being a dark blue, every little thing will help to keep the waves less noticeable.

 

This was interesting...

There was body filler applied at the top of the C pillars at the front edge. I'm not sure if all cars were like this to cover up or refine the shape due to a design flaw or if my car was incorrectly assembled in this area. When I do the final blasting for the t-top channels, I'll remove the filler to see what's up underneath.

 

I've heated and mildly reshaped bumper covers countless times over the years. Although, I've never tried removing the 'sag' from the large area you speak of on the front cover. You may need to form some type of wooden buck. If the plastic isn't held in place as it cools, it won't stay where you want it.

 

A buck is a good idea, thanks.

 

My '83 had the same body filler in the C pillar at least on the driver's side from what I remember. I figured it was for the contour to match the weather strip gutter. I sanded it all out and thankfully there was no rust underneath.

 

Didn't think that there might be rust hiding there. Crossing my fingers.