S&S Header Modifications.

[3X00-Modified]

This fits a 3400 4t60e and 3400 5-speed combo (after grinding bellhousing on 5-speed)

The 3t40 needs some more work on the #1 cylinder.

Here are some pics of the modifications I had to do to the S&S headers to get them to fit my car... Also pictured is Erics unmolested set... which will soon receive the same treatment.

A few notes of things I did was cut all three tubes at the back flange and bent the main header down further to give it a sharper angle, then shortened and angled the last collector in the opposite direction so it wasn't aiming so far down. And lastly re-aligned the cross over pipe again.


Completed header

Last collector cut and weld.

Cross over hacks, It could have been done it one cut on each side but since I didn't have both on the same motor it took me two or three shots.

Bottom of rear down tubes.

Angle of mine

Comparison to unmodified... the rear flange does angle it a little more too since its not flat.

Collector comparison

collector flatness comparison.

[3X00-Modified]

I know this pic had been done before but it was with a manifold and a S&S stock to compare... here is the header that works and a factory S&S so you can see how much I modified it down to fit.

All chopped up!!!

I had to add 20* to get the angle right.

They don't call it a 60*V6 for notin... LOL

What I started with

Right now the tubes are welded back up and set for a 60* angle on the mock up motor. Remember that's not a definite measurement, that's what it ended up being after I removed the DIFFERENCE... That's all you need to remember and tweak for.

[Asylum]

Jon did a GREAT job modding mine, and the 3t40 additional change is just some "persuation" a few inches down #1 pipe, approximately 6" long.

I will post a pic when they are off over the winter if no one else beats me to it, although I may have the ONLY 3t40 set, LOL.

Unfortunately mine had to be "persuaded" after they were ceramic coated. At least you can't see it back there.

[Barry]

The modding for the Pace setters is pretty similar...

Cut the back one at the flange and algle it just a tad over 20*.
The crossover pipe has to be compleatly re-made.
Front header needs no work. 5-speed bell housing needs a grind, looks like it will clear the auto.
OPSU needs to be re-located, need to swap in a 96 fan.

[Asylum]

Actually I kept my '92 huge fan.

Just cut off one of the four spokes.

It's actually still plenty strong enough.

But the later fan is a better choice. Smaller and probably more efficient.

[Barry]

Yeah, I had a look at both of your headers at NE fest, the front is totally differnt than mine. Mine only has about a 1/4th of an inch between header and fan(96 fan)

[MY91GT(Z)]

they did fit great and had i thought about what woody did by just dimpling it some but the rear header had no problems

[3X00-Modified]

The modding for the Pace setters is pretty similar...

Cut the back one at the flange and algle it just a tad over 20*.
The crossover pipe has to be compleatly re-made.
Front header needs no work. 5-speed bell housing needs a grind, looks like it will clear the auto.
OPSU needs to be re-located, need to swap in a 96 fan.

I guess there is a good reason why I went with the S&S ones... My OPSU is in the same spot as stock, just has a sparkplug sock on it to protect the wires, and I also put a sock on the closest heater core line. I didn't have to move one other wire.

[Forced_Firebird]

Nice job!

I have a few ideas to change things around a bit so my headers will fit a little nicer.

First of all, I don't know why the collector needs to be almost rubbing the t-stat housing. With it's position, the #2 primary is 27" long vs the #6 being 16" and all the rears are 12". Moving the collector a little closer to the corner of the head and having the crossover start earlier, then I believe it will make them fit most of the transmissions. Also the #1 primary can be moved a little closer to the others so they won't have to be dented. Still unsure about how the final collector should be finished to make it easy for the end user to install them without going to an exhaust shop though...

[Asylum]

I like the thought on the T-stat!

The S&S is very close and would be a royal PITA to change the stat. It seems, at least on my car, that there is alot of room to bring it out some.

[3X00-Modified]

First of all, I don't know why the collector needs to be almost rubbing the t-stat housing.

Funny thing is, thats not L-body specific either, since the T-stat housing is the same on the N's and such that use these. Maybe they have more space restriction in that area than we do... Anyone look in a N-body bay in that area?


Yeah IIRC I also have plenty of room to have the collector move from where it is.

I did the lower portion of my exhaust as well and didn't go to an exhaust shop, I've only recommended that to others since they are sending them to me because they don't have welding skills or tools, and I can't get the collector right without putting them in a car... at the time I did both sets I had only the mock motor, and no car to test fit into.

I replied to your other post on here about possibly shortening the length of the rear header some to bring the collector up, then you can make it a straight shot and provide the flange and ~45* bend needed to send it down the tunnel.

[IsaacHayes]

John, what do you think about the clearance pic of the sway bar I sent you? I think for end there, having a 3 bolt flange is the thing to do. But then again I could use a band clamp like the rest of my exhaust is... Keeping it short as possible where it comes back to connect to the rest of the exhaust would work for me with where my cat is and I wouldn't have to dissemble the whole exhaust to cut the stainless more... That way there is also more room to install a stainless flex piece. I'd probably weld the SS flex to a 3 bolt flange, then connect that to the cat. I'd rather have to add pipe than remove pipe and move the cat back for my application. Not sure how others setups are, but keeping the cat forward is better than moving it back for efficiency of the cat purpose too. The flex pipe will add a lot of length before the cat too.. 3 bolt flange welded to a SS flex would be a nice option to have, That way you just bolt it to the header then connect the flex to the rest of your system and you're done.