Installing 1 5/8" SLP headers on my 91 Formula 350.

1. How the heck do you get the second from back bolt off on the passenger side. You have to use a deep socket because there is a stud on the bolt that sticks out for the heat shield. I can get deep socket on but that leaves about 1/4" space between the end of the socket and the big plastic housing that I guess is Air conditioning/heater housing. The only think I can see is build a special tool by either cutting the socket down a little, or weldin a 3/8" Square metal piece on a metal bar and using it for a wrench on the socket. Wrench will not work, closed end is too thick and open end wont go on either.?????

2. What do you do about the dipstick on the same side? Can it just stay there and put the new headers over it?

3. I assume it is importante to reinstall the metal heat shields in the same position. Kind of messed them up getting them out

4. What did you do about the plug wires? The stock looms obviously will not work. Did you buy custom looms, where did yoiu put them? Would love to see a pic.

Barry, if you read this give me a call, I was going to call you today

 

I installed my 1 5/8 headers couple of years ago. Mine came with the header kit. To answer your question:

1. I actually used a wrench to get the bolt off. Took time but it came off.
2. I took the oil dipstick out when installing the headers. The headers will have provisions for you to bolt your dipstick to the headers.
3. I did not use the stock heat shield. At the time, I didn't know if it would work or not. I did get a heat shield blanket for my starter.
4. I bought accel wires that are 90 degree.

Some useful hints. Now is the time to put in new spark plugs prior to bolting your headers on. For your fan switch, make sure you have an elbow adapter so as to install and remove your fan switch easily. (My kit came with one.) If and when I do my engine swap, I plan to use torq bolts to replace the current header bolts.

 

On the hard to get to bolts it is easiest to go at them from underneath the car using a crows foot, be sure you have 6 point bolts when using the crows foot.

 

Pull it out and reinstall it whent he headers are bolted up.

 

Ditch em.

 

You will be best off with 90* wire boots.

Get some aftermarket looms, there are tons available.

 

Thanks for the help

Ive got new Platinum plugs ready to put in. I guess just put them in with the headers completely out, or position the headers in there, then put them in before bolting?

When you say 90 degree wires, you mean plug wires were the boot is shape like an ell (L) instead of straight i guess. I have MSD wires and I think all of them except the back ones on each side are straight. Can I buy a kit and use the same wires, that would be good anyway, I could cut everything to fit right, then install the 90 deg boot on the end. I guess you need 90 deg so as to come up through the headers and run the wires along the top as in the pic (nic pic) right?

Does the dipstick just pull out? I felt around up under the starter and I dont feel any bolts. Do you have to take the starter off to get i back in? I cant see behind there

Im going to try that bolt with a wrench again, open end. By the way, what is a crows foot? IM not optimistic for success with an open end wrench. I am doing that one from underneath

Those looms in the pic look nice. Are they actually attache to the headers of what. There is no problem with melting wires without the heat sheild?

thanks again

 

Put the plugs in prior to bolting up your headers. It is a tight squeeze once your header are bolted to the motor.
90 degree are the shape of the boots. You are correct. All my boots are 90 degrees. Just take them back and get the ones that are all 90 degrees.
The dipstick will pull out once you disconnect the nut holding them to the old headers. The dipstick will bolt up to the slp headers.
My plug wires have not melted yet and I don't have a heat shield except what I put on my starter. Using a wire loom is a good insurance from keeping the wires off the pipes. They also sell plug wires that can withstand high heat.
One more thing, when you do start your car up for the 1st time with your new headers, do not be alarmed by the smoke or smell coming out of your engine compartment. Thats just the impurities burning off the nheades as well as the gasket setting in.
Here is a pic of a crows foot:

 

OOPS here is the pic of corws foot

 

Got the passenger side stock manifold off. Everything went ok after getting rid of that pesky dipstick. That sucker was a bear to get out, not looking forward to puttings it back in. After that the heat sheild came right out and exposed the two remaining header bolts from underneath. The only way I could get the second to back one was with a open end wrench. After everything else was out I was able to get it on just enough to break it.

Now comes the fun part of putting on the new ones. One question, why are some of the bolt holes on the SLP headers for longer bolts? I bought a set of stage 8 bolts and they are all short. I guess I will have to reuse a couple of the longer ones from the old ones. What size bolts did you use for these longer ones?

thanks

 

I bought my slp heaer with the kit. (had the bolts and so on) Make sure you get an elbow fitting adapter to put in place of where your fan switch sensor goes. You can probably find one at Home Depot. As far as the oil dipstick, why not go ahead and replace the "O" ring since you have it out. Hope this helps.

 

How's it going Larry?

You are going to have to use 2 of the stock long bolts (the ones with shanks) in order to re-hang your compressor brace bar and your alternator brace bar.

 

HI, well its going. It took my Sat and Sun (working about 1/2day) to get everything off. Passenger side was an adventure. After hearing about all these littel things, I decided to order the installation kit from SLP yesterday. Maybe its a mistake at this late date, but Im going to wait now until it gets here, probably FRiday or at the latest by MOnday. In the meantime Im cleaning the engine bay, installing new spark plugs. Fortunately the car is not every day driver, so I can let it sit as long as I want.

I was wondering about those braces. Im going by memory but as I recall, the alternator brace wasnt on a header bolt, but a separate bolt. I will double check later tonight. The AC brace was definitely on a stud of a header bolt. So that will have to be reused. But what Im confused about is several of the holes on the headers have about 1" sleeves on them, and the others don't. So the ones that don't could use the stage 8 header bolts wich are bout 1 1/2" or so, but the others will require the longer bolts from before. I need to look and see how many and where they are. Anyway Ive got a little time now.

Do the headers have a place to connect the dipstick, or does that come in the kit too?

It looks to me like I will have to remove the gas lines on the drives side, and the air compressor on the passenger side to get the headers in. Wee,

I want to leave off AIR tubes, and smog stuff at least for a while. I just got it inspected a few days ago, so Ive got at least a year. The only thing Im not sure about is what to do with the pump. Somebody said it will sieze. I don't really know what it pumps, in other words what is the input and output. I know that the metal bracket I took off connect to the AIR tubes so that must be the input, and it pumps the exaust gases back to somewhere right? Why would it sieze then if it is just pumping in air from the engine compartment.

lots of questions I know

See you at the gathering, with new headers ( I hope LOL)

Larry

 

1. When removing the headers, passenger side will be an adventure same as installing. Wait until you try to bolt the last bolt closes to the firewall on the headers. The SLP will slide in easily on the passenger side; the driver side will have a tough time installing. I installed the driver side without having to dent my headers or grind the steering. Just take your time and massage it in.
2. Getting the Kit is a good move; you have everything you need to install the kit. Still would go with the torq style bolts next time.
3. Check your passenger side header and look at the #6 pipe. It should a hollow sleeve welded to pipe. That is where your oil DS will go.

 

Yeah, got it. I looked at the headers a little closer last night and, of course, everyone is right. The alternator bracket does bolt to a stud on the front header bolt on the driver side. Also I did see that sleeve on the #6 pipe. I guess something comes in the install kit to use to attach the dipstick. It seems like getting that thing back in will be a *itch, as you have to bend it around a corner, stab it in the little hole then mash it in about 4" into the crankcase.

I have the 1 5/8" headers so Im hoping for no issues on steering column clearance. I got the back three bolts on the passenger side stock manifolds off from underneath, Im planning on putting them back on from there as well, although now that I think about it, the collector will be in the way from underneath with the headers, where the short stub off the stock manifold wasn't. Ouch.

I also looked more carefully at the width of the bolt mountings on the headers. On the Drivers side (starting from the front), the first and third bolt mountings have about a 1" sleeve on it and the others don't. So I can use my Stage 8 header bolts for the other 4, but will have to reuse old bolts (or buy new ones) for the other two longer ones. #1 bolt has the stud for the alternator bracket so I guess the sleeve allows you to reuse the old bolt/stud. But the #3 bolt doesnt have any stud or anything attached to it, so what is the purpose of the sleeve?

On the passenger side the #1 bolt has about a 1/2" sleeve, #3 bolt a 1" sleeve, then other 4 normal. #3 allows you to reuse bolt/stud for attaching the AC bracket, but why does #1 have a sleeve?

Anyway, I guess these are the great mysteries of life

 

Now you can see why header installation is so pricey!

 

Thanks for all the tips, I don't know what I would do without this board. Im installing the headers finally this weekend. The installaction kit came. I do not see any elbow adapters for fan switch sensors with is disappointing, since that was what convince me to finally buy the installation kit. Anyway Ive got the fan switch sensors out and am heading to home depot. Im assuming what you guyt mean is to install a brass 90 degree elbow into the block so that the sensor can be screwed into that and point downward instead of out to the side. This will allow removal and changing of the sensor when necessary much easier right? I notices that the sensor goes fairly far into the block. Will it still work OK when its in a 90 degre elbow, farther away from the engine. Should I do this on both sides, passenger and driver? I had to buy a new connector on the passenger side since the old one turned to dust when I took it off. ONly $15 from GM, but it does come with a free butt splicer
Anyway, let me know. By the way, what are the heat shields in the installation kit for. Head wires or some such think according to the instructions.

thanks

 

Sorry to hear that the kit did not come with an elbow adapter for your fan switch. Have you tried putting the passenger side headers (just holding it in place) while the fan switch is in the block? There is not much clearance and your wires will be touching the header. I've had no problem with fan coming on using the elbow. (Don't forget to put more coolant directly into your engine by the thermostat housing.) Only need the elbow for the passenger side. Heat shield sleeves goes to your fan switch/wires. This is all I used for my set up. Make sure you have the elbow, fan switch and wires connected prior to bolting the headers.

 

Well, I am sorry too, since that is the final thing that conviced me to buy it. I bought it from SLP for these headers. Whatever. I found brass fittings at the hardware store, but I worried that it will work properly. I have a stree elbow (male thread on oned side of th 90 deg, and female on the other) that will screw into the head. The female part is too shallow for the sensor part to fit in and engage the threads so I have to put a close nipple,then a coupling and screw sensor into that. Two worries, one, now the sensor is farther away still from the block, and two, coolant will only come into contact with the bottom surface of the sensor, not the sides like if it was screwed directly into the head.

Do you think it will work? is that pretty much how yours is?

Yeah, it dawned on me that "head sensor wires" are the wires to the two sensors, I put the heat shieds on last night.

I guess I will try it with elbow stuff. Im have been thinking about installing a manual fan switch anyway. I guess if it doesn't come on soon enough I will just turn it on. The car is not a daily driver anyway, and I wanted the fan switch for the staging lanes at the track.

There are two whitish cylinder about 1/2" diameter and about 2" long. They call them AIR connectors or something. What the heck are those for? Im not going to connect the AIR right away anyway, but it would be good to know

 

Larry

Are you running the stock fan switch?

If you are it is pretty much worthles anyway. It doesnt kick the fan on till 235*

Just some food for thought, before you go through this hassle you might want to think about a Hypertech, Jet, or GN fan switch.

I opted for no switch and hard wired the secondary fan to a switch in my dash, and just plugged the head.

Isnt the header flange notched for the switch anyway? When I installed my Hooker LTs, I know its a differnet product, I would have had no problem installing the switch, as a matter of fact I installed the plug after everything was all bolted up.

Anyway I am with you, header installs suck in general.

 

yeah, its a stock fan switch but the chip is custom, I it turns the fans on at 82C which is right at 180F. Thinking about that, I wonder if I really need the temp switch? Anyway I didn't put in the elbow, and the heat sheild material lies right on the header. If it burns up Iguess I will take it off and either put the elbow on or just leave it off and do a manual switch.

Hey, a question. I was missing the bottom flanges that bolt the collectors to the Y pipes, so I orderd two from SLP. I turns out the ones they sent me have threaded holes the same as the upper ones that are on the collectors. I think the bottom ones just should have nonthreaded holes right? The bolts that came in the installation kit are not all thread. They wouldn't work with threaded holes on both sides, wont' reach. Im thinking about just drilling out the threaded holes in the bottom flange. How did yours comoe?

 

The ECM only controls the primary fan.

The secondary fan it controlled by switch in the head and with a pressure switch in the AC system.

If the AC is on the secondary fan kicks on.
If the temps hit 235* the secondary fan kicks on, this is a function of the switch in the head.

 

Gotcha. So the chip will lower the primary fan temp, but to lower the secondary you need an aftermarket switch that closes at a lower temp.

What about the flange question? how did your flanges come?

 

Exactly

The secondary fan is switc controlled only.

I have Hooker 2210 LT headers, the falnge was notched for the switch. But i plugged the hole and set the fan up for maual operation as I didnt want to pay 40$ for an aftermarket switch.

 

No, Im asking about the flanges that connect the collectors to the y pipe

 

on my headers, the y-pipe flanges were just straight holes, the headers flanges were threaded.

i bought the install kit and got 4 silver bolts with lock washers, they worked great.

 

Alot of times both flanges are not threaded.

You just use a nu and bolt to tighten em up.

 

You can grab parts for your fan switch elbow at the hardware store. If I remember correctly, it is a 3/8" pipe thread. I used a male/male coupler, a plug, and a triple female T fitting. That's what it took to get the depth I needed for the fan switch I'm using (which was longer than the stock one for some reason).

As far as wire looms go, you should have centerbolt valve covers, right? I think the earlier pic posted by somebody showed a nice arrangement on perimeter bolt heads. Search for the Made For You centerbolt wire looms (maybe Made 4 You). I'll admit that they are pricey, but I was glad I bought them for mine.

I don't think you'll need this since you got the installation kit, but I am pretty sure that I've posted the part number for the "donut gaskets" for the collecter to y-pipe joints.

Hope it all goes well,
MikeS

 

Perfect. I got the headers new, from a guy, and when he shipped them the flanges on the y pipes fell out of the box and were lost. So I ordered new ones from SLP, but the dweebs there sent me the same ones that are on the collectors, with threads. I also got the four bolts, nuts and lock washers in the install kit, but they dont' work with both flanges threaded. So thanks, that confirms that I just need to drill out the threads on the ones I got for the y pipes from SLP. Of course I asked the guy when I ordered them if they were the same, top and bottom, and he said yes. WRONG!

 

[QUOTE]Originally posted by MikeS
[B]You can grab parts for your fan switch elbow at the hardware store. If I remember correctly, it is a 3/8" pipe thread. I used a male/male coupler, a plug, and a triple female T fitting. That's what it took to get the depth I needed for the fan switch I'm using (which was longer than the stock one for some reason).

As far as wire looms go, you should have centerbolt valve covers, right? I think the earlier pic posted by somebody showed a nice arrangement on perimeter bolt heads. Search for the Made For You centerbolt wire looms (maybe Made 4 You). I'll admit that they are pricey, but I was glad I bought them for mine.

I don't think you'll need this since you got the installation kit, but I am pretty sure that I've posted the part number for the "donut gaskets" for the collecter to y-pipe joints.

[QUOTE]


That is a good idea on the fittings for the elbow. Yes they are 3/8 thread. I bought a street elbow (90 deg with male on one end, female on the other), then had to use a male/male coupler (close nipple) then a female/female coupler to thread the senor in. I didn't like this because one, the sensor is pretty far away from the head now, and two, the only part that is exposed to the coolant is the bottom surface of the senor. I see what you are saying though. It seems that the sensor would be closer to the head and would actualy stick out into the tee a bit. Im going to try that. As it is, I put the sensor directly in and then used the head shield over the wire and connected the connector. The heat shield lies right on the header and unless it is really fireproof, its going to burn up when I start it.

Got the Made for You wire looms. Very nice, $50, definitely pricey

Donuts came in installation kit, thanks

 

Is ther a trick to getting this damn dipstick back in? It was very hard to get out. I hope I don't have to take the starter off since the hole is behind the starter. Also, someone said it would be a good idea to change the o ring. Where the heck is it, how do you change it? It's not on the dipstick. This is the last thing I have to do. finally!!

 

there isn't an o-ring on the dipstick... at least not on any pass. side dipstick i've ever seen you know?

as for fitting it in....it should be between the last two pipes closest to the firewall...i find using a REALLY bright light....aka maglight helps when trying to locate it from above.


good luck i know it's been trying on you.

 

Well, yes its been difficult now and then, but I have learned a lot, just like everything else I have undertaken. Like I said, I could never do stuff like this and take three weeks to do it if it was a daily driver, so I guess Im lucky. Im sure if I do a header installation again I could do it in 1/2 day easy. I highly recommend that PB blaster bolt loosener stuff. I had no problems at all getting out the old header bolts using that.

I drilled out the flanges that connect the y pipes to the collectors like I said but the bolts in the stupid SLP installation kit are way to short, only 2" long. I bought 2 1/2" last night and those are too short so Ive got to get 3" one. All in all I would say if you know what you are doing you don't need the SLP installation kit. the only thing I used really were the header bolts. The stage 8 ones I bought did not work because the hex head does not allow a socket to fit between the bolt and the header and you cant use an open end wrench of a lot of them. The heads on the ones in the SLP kit are 12 point, and smaller, so you can use a 12 point socket, which is thinner to begin with, and get a better grip too.

Next time I would just buy the following

- 12 point header bolts
- heat sheathing for wires close to the headers
- gaskets
- fittings for the elbow on the sensor

by the way, I used the same custom Accel 8mm wires and bought 90 degree boots and a crimping tool. Cut them to fit for the made for you looms, worked great and looks good. Will post a pic when all is done.

 

Did you get the dipstick?

Just get it started and then tap it in the rest of the way with a hammer, moving and wiggling as you go.

 

I recently put a new dipstick tube in and know what you mean. I actually had to bend mine into a tighter curve. That way it could be lined up with the hole in the block and not be wedged against the heater box. I don't know if that's your problem or not. If it is and you have to bend it, be very careful not to kink it! With aftermarket tubes (mr. gasket), I've had to sand them slightly to give them a taper and get them to fit.

I doubt you'll have to get heat shielding for your plug wires. I've never had any problems with mine being exposed to the headers. The looms keep them where they should be and the heat isn't a problem as long as they aren't laying on the tubes. Sounds like you're almost ready to turn the key!

 

I reused the old dipstick, no money left for new one. It actually wasn't bad, stabbed it in the hole, then ones it was lined up it slid right in.

Double checked everything and started it with just the open y pipes last night. Got quite a bit of smoke at first, as was mentioned on here to be expected for first time starting. But it runs good and the smoke died down pretty quickly. Looks good, sounds great!!! Kind of hate to put on the Cats and muffler.

I left the AIR off, just plugged the openings in the headers with a cap. Is anyone aware of any problems I can have with this? I don't think so.

I just disconnected the fan switch and wired a manual switch.

I only ran it for about 5 minutes so far. Today Im driving to the muffler shop to have the cats welded up. How would I know if I had an exaust leak? Would it be obvious?

 

Thanks to all that gave assistance. Like the superram installation (see thread "I hate superram") all the headaches are forgotten once its on and looks and runs great. I ended up wiring a manual fan switch and just leaving the fan sensor plug off. Probably would not have done that on a daily driver.

 

I sure like the looks and the ease of working on the motor without all that AIR crap. I kind of wish I would have bought headers without AIR now (note caps on header and CAT AIR). Oh well, this way I can put it back on fast if I need to for emissions.

 

No problems with steering column clearance. Its pretty close though. These are 1 5/8", the 1 3/4" might have hit.

 

Looks good

 

Good job on the header swap. The only think I don't like about your engine compartment is the superram. Doesn't look right, take it off and give it to me. LOL. The only thing I would do differently regarding putting any type of headers would be to go with the torq style header bolt. Again good job and enjoy the fruits of your "labor".