So what kind of exhaust would you recommend for a 421sbc making 550 crank hp and a 250 shot of nitrous on top?

 

Dyno Don, any advice?

 

Go with my headers, dual 2 1/2", two cats and feed into a 3 1/2" cat back.

 

Just got an e-mail saying that my headers and downpipes shipped! Can't wait till they arrive.

Don, I am getting your dual cat downpipe, and was planning on going full 2.5" back into (2) 2.5" Magnaflow super converters and then continuing dual into (2) 2.5" Borla XR-1 Mufflers, what is your opinion on this set-up? (I am going to get a local shop do the piping custom, going to be all 2.5" and mandrel bent, most likely out of stainless)

 

I picked up my headers from Don at his show this morning. I am more than please with how they look and the quality of the welds. I will get some pictures up here in the next few days. It was a pleasure meeting you!

 

Question is, when is he going to start making us turbo headers

 

Here's mine:

 

I think one of the greatest features is the thicker Flange. I made 442 rwtq Dyno Jet so any 406,396,383,355,350 tuned they work great and I think it's worth it to go Dual converters if you want the more power. We all know that!

 

is the dual converter pipe set up purchasable WITHOUT the cats??

 

The front part is, the rear is custom for each car.

 

Headers and Downpipes arrived today! Hopefully I'll get a chance in the middle of this month to get my car into a lift-bay and start tearing it apart.

I was just curious on your input Don, and an exhaust set-up I was planning.

It would be dual 2.5" magnaflow cats, (after your dual downpipes) into 2.5" dual stainless steel mandrel bent piping, into dual 2.5" Borla XR-1 mufflers, would this be a good set-up?

 

3-3.5in cat back would be the best way to go. Less headache for installation and less money. It will perform better without the extra noise.

 

Ill be ordering my headers and Y Pipe from Don pretty soon.

 

Don, question for you. I'm thinking about swithcing to your headers and the dual 2.5" pipes with a 4" Mufflex catback instead of my current setup due to ground clearance. Currently I have the 2210 longtubes with a 3" y pipe that only gives me 4" of ground clearance at best. They had a hard time fitting the exhaust around the UMI crossmember with the driveshaft loop. My only fear is restricting the motor it's a 406 with dart 230 heads, solid roller, 11.6 compression that I shift at 6800.

Thoughts?

-Jim

 

I have a couple of 406's running my headers, they are working great.
400 + to the rear wheels

 

This motor is 650-700hp at the flywheel

 

Wow, 650+hp for a 406.

What did you dyno to the tires?

I have friends that have 421sbc's that are 600+hp and they are using 2" headers with dual 3.5" pipes over the axle. They are also shooting 250+hp nitrous too.

 

Haven't dyno'd it in the car yet putting it in over the winter, what does your current motor run on motor?

 

13.0 on the motor. Unfortunatley my 400 has 9-1 compression.

 

Well, I went to install my Dyno Dons headers, and the drivers side header fit in with no issues at all. As a matter of fact, I have more room than I did with the TES headers I had on it before.

The passenger side is a different story though. It looks like I need to relocate my fuel lines?? They run from underneath and wind up along the top of the frame - and the tubes are hitting them. I bet original TBI and TPI cars have fuel lines routed differently. The header tube is hitting in the same spot where when you run the TES headers, you need to put insulating wrap around the lines due to the tight clearance. With the Dyno Dons, it's too tight....

Anyone else run into this issue?? It looks like I'll have to relocate/bend new tubing because no matter where I run the lines, it'll be close to header heat....

 

Just a little modding to your fuel line and you're ok. I think they were design mainly for TPI and TBI 85-92. 82-84 fuel line are routed different for Carb engines but they will still work for all 3gens

 

What motor mounts are you using? I had issues with fitment on passenger side with poly motor mounts. Not with fuel lines tho.

 

TPI cars have fuel lines on the drivers side, if you are running poly mounts you need to tell Don as he can compensate for that, I did and mine fit fine. I'll say it again I am very happy w/ my headers, performance and quality wise...

 

Thanks for the replies everyone. I was hoping someone else with a 82-84 carb could chime in as I notice no one that responded has one.

But I'm thinking VincentZ28 is probably right....Don's design was mainly for 85-92 cars, and J91 says the fuel lines on TPI/TBI cars are on the drivers side. I have more room there.

Well, mine are/have always been on the passenger side. And I'm running stock rubber OEM engine mounts, nothing fancy there. Again, the only interference I see with my passenger side header seems to be the fuel lines....looks like I'm gonna have to either "tweak" them somehow, or totally re-route them...somewhere...

If there's anyone out there with a 82-84 model that's installed Don's headers, I'd love to know how you routed your fuel lines...do you need to re-bend new tubing??

Here's a few pics to see what I'm trying to say...



EDIT: Also - I'm not saying I won't be happy with the headers once I figure this out...they're built really well and just have to breathe better than the Edelcrock TES's I took off the car (which were close to the fuel line, but fit)...you can see the insulating wrap that came with the TES headers around the fuel lines in the pic...plus remember, these '83 HO cars had issues with vapor lock from the factory due to the stock exhaust heating up the fuel lines too much...bad design.

 

$775 (no A.I.R.)-$815(w.A.I.R.) for headers w/y-pipe? YIKES! I know the expression "you get what you pay for" but still...That is a heap of $ I have no need for ceramic coating around here. Too dry, no road salt & I have yet to ever see a set of headers rust out around here.

 

I have a 83 and I had the same issue. Mine was a crossfire car originally and only had the one line on the right side. The previous owner cut the line back further just before where it goes over to the other side and used rubber line from there and that did work for clearance for the dyno dons. When I switched over to efi, I just cut the line on the left side where is crosses over and ran braided hose from there and removed the crossover pipe. On a side note, on the pass side, does the flange on the bottom hit the control arm mount because I had to remove a chunk of it so it did not bind on it.

 

I have Don's headers on my 1984 L69, no problems at all with the fuel lines. /shrug

 

Your the 1%
Just imagin what SLP would charge for these headers today! holy cow, prolly dubble Dyno Dons price!

 

Here's a couple of pics of mine installed. The lower flange pic is before I removed some of the metal to fit them better. You can also see where the previous owner rerouted the fuel line up and out of the way. Sorry its a bit of a mess in the pics, I swear its better now.

 

Wow, thats crazy close!

 

That sure is purty! OK I'm jealous both that I don't have any and that I don't have the horses to need them

 

Alright, so I just took the manifolds off today, I have a few more things to remove before I begin the install, but I have a few questions.

What bolts/studs has everyone used for the collectors. Has anybody been using specific part #s or anything, or just bolts and nuts? I'm not sure as to what to use, so I was hoping to find some help here.


Also, the braces that are attached to the AC and the Alternator. What have you guys done with them, have you fabbed them up to be attached somewhere else, or have you just left them off?

 

Here's something that nobody never knew. You can move your engine over to clear the fuel lines by switching the engine mount bracket to opposite side. Those brackets are right and left. They are not the same. Have you ever notice on the Camaro's that the air snorkel is not straight with the throttle in some cars? In some cars also, the K-Member is slightly to the right. Take a close look at the front tires. These things make a difference how the engine sits in the bay. This may be the reason why some people have fit mate problems.

 

Odd.
All my motor mounts and shells that mount to the motor are the same for left and right side.

 

Dyno Don brought the brackets to my attention when we were discussing how close it was to the pass side. Mine are reversed, but if I were to switch them back, the flange on the bottom would interfere more that it did already and would be too close for comfort on the left side. The left side now fits absolutely perfect. I did not know about the k member, I will have to look at that.

 

It's just like you heard that SLP 1 3/4 headers hits the steering shaft in some cars. In my car I have a 1/4in clearence. So some cars will have a great fit with no issues and some will have slight issues.

 

Are we talking about the engine mounts that bolt to the frame, or the ones that attach at the engine??

I didn't notice any difference in mine between one side and the other. I certainly don't want to go through the EXTREME hassle of switching them unless there's some way to tell one from the other (Drivers vs. Pass)

 

I just had my mounts off of my 92 formula a few weeks ago. Both of them, on the motor and the subframe.
They were both the same left and right.
I'm guessing the part #s would be the same..

 

That's what I'm kinda guessing too....I do know that engines are almost always off-center to the right...thats normal. It allows room for the steering box etc...

 

Well it's true. I found out the hard way too.

 

In addition to those 2 questions, I have one more. I've heard that with certain headers it is no longer possible to change the spark plugs with them in (Due to the primaries blocking where the socket would be). I was planning on leaving my plugs out until I got the headers in so that I didn't have to worry about snapping any off while positioning the headers, does anyone know if it is still possible to insert the plugs after the headers are in place?

 

Since you're using Dyno Dons headers, you don't have to worry about changing spark plugs. There is plenty of clearence and you can leave them in while I stalling the headers.

 

This is handy when you change plugs at tight places: http://www.summitracing.com/parts/SLE-30102/

 

I guess I still don't get it...what's true?? Again, HOW would anyone know if the mounts were switched to the wrong side - They both look identical.

I've also replaced both my frame and engine mounts in the past (a good 5 years ago) - and had Edelbrock TES headers on it without issue. They fit..

 

The mounts are the same, left and right.

 

And that's exactly what I always thought...after searching, I only found this thread that "kind of" addresses it, but it's not definitave....
https://www.thirdgen.org/forums/engi...de-engine.html
And they're talking about the clamshells that go on the engine - not the ones that bolt on to the K-member. I'm going to check mine out, but I don't think I can see any numbers on mine....

 

All of my factory mounts are the same.. I'm sure the stampers and hole punchers were off a lil bit every now and then. Now throw in aftermarket replacements and they can be waaaay off.

 

Agreed. When you talk aftermarket stuff, all bets are off. But I'm running my bone stock, original type mounts on both the frame and engine. I've looked at these suckers off the engine more than once when they've been off the car, and they looked the same to me. Didn't look like it mattered at all no matter which side they went on.

 

My brackets did have two different part numbers. They are on the inside of the bracket. I don't however recall what the numbers actually are. It was really hard to read them installed on the car and I could only make enough to know they had different numbers and which side was which. Maybe dyno don can chime in with them because he originally gave them to me and I have since deleted the PM. I do have to agree with anything aftermarket. Fitment always seems to be a gamble. Overall though, as far as his headers, I am satisfied with them. Look good and perform equally as well.

 

Actually I can see a part number on the front side of my clamshell bracket on the passenger side - I can make out these numbers clearly.."40394"

I'm guessing that's part #14039436 which is on the passenger "right" side, so it's safe to assume the other clamshell is part "334971" on the Driver's "left" side since both of these are original to the car.

So- from what I'm reading on this thread at least:
https://www.thirdgen.org/forums/engi...de-engine.html
They are both on the proper sides. Guess I'm going back to bending new fuel lines....