Headers Headers Headers

[blackbombshell95]

well are they any 3400 headers (aftermarket) that will bolt right up to my 3100? i have a 95 grand prix.

[ikessky]

well are they any 3400 headers (aftermarket) that will bolt right up to my 3100? i have a 95 grand prix.

Yes, the TOG and S&S headers will both bolt up to your 3100. However, you will probably have to get them modded to clear your firewall.

[blackbombshell95]

TOG and S&S headers, where can I get them, and for what application will they say that they are for? so how much work is it to take off my old headers and put new headers on? do you k now what kind of modification is involved?

i' might sound stupid for asking this question, i'm just learning about cars, thats why i'm going to college in september to be a mechanic, the firewall is lol, WHAT. the cover over my exhaust manifold, what keeps the engine seperated from interior of the car?

[blackbombshell95]

oh duh tog, the other guys headers. stupid me, i'm sure they are expensive.. what modifications should i have to put headers on? performance wise.

[blackbombshell95]

one last question, what year grand am 3400s will work with my 3100.

[ikessky]

S&S headers were designed for the '99+ Grand Ams (with the 3400). The front header will fit fine, but the rear header will probably have to be modded. You will have to cut the rear header, give it some new bends, and then weld it back together. I'm sure any exhaust shop worth their salt would do this for you.

You don't need to do any performance mods to put the headers on. Of course, their effect is going to be increased with anything you do to make the intake breath more freely (this includes head work).

The firewall is the wall that seperates the passenger compartment from the engine bay.

Any year 3400, regardless of what model it was in, will work in your engine bay.

[bluebomber]

So the crossover with the S&S headers works just fine on 3100 automatics? Only modification is due to clearance issue on the back header? Am I understanding this correctly?

[ikessky]

As far as I know, yes.

[bluebomber]

Hmmm, this could be my next mod.

[RacerX11]

No i dont. but you should also know that factory 3.1 manifolds fit with no modifition onto a fiero.

I think its more a "urban myth" than fact to say they are not interchangable.

I took a set of fiero manifolds and they bolt directly to a 3.1 AL head

You should know that your experience is not the norm. There must be something different about your Fiero engine. I'll say it one more time: the exhaust manifold bolt hole spacing is different between the gen1 iron heads, and the gen2/3 aluminum heads. The gen1 heads have 56mm spacing, while the gen2/3 heads have 64mm spacing.

I have measured gen1 heads from an '84 Citation, '85 S-10, '87 Fiero, and '91 S10 (all 2.8's). The spacing was the same on every one (56mm). I also have 3 pairs of gen2/3 heads ('91 3.1, '96 3100, and '99 3100). They all have the 64mm spacing.

Here is a picture showing a '91 3.1 manifold up against an '87 Fiero head. The 3100 manifold is the same. Tell me how exactly this fits with no modification?

This 'urban myth' sure seems to have quite a bit of evidence backing it up. There is something different about your engine that is not representative of others.

Marty

[RacerX11]

Here is a measurement of an '87 Fiero head on the left, and a '91 3.1 exhaust manifold on the right. Notice the difference.

Marty

[donk_316]

I dont know what to tell you. I took the 3.1 manifolds and bolted them to a fiero, and visa versa. I have a complete 3.1 top end in my shed and ofcourse 2 fieros in my drive way. hell the 3.1 manifold bolts to my 3100 head too.

Thanks for the pics though. Ill take my 3.1, 3100 manifolds into the shop and see whats up. I know of another guy who found the same thing as I did too.

[RacerX11]

[quote="donk_316"]hell the 3.1 manifold bolts to my 3100 head too./quote]

The 3.1 and 3100 have the same bolt pattern, so this is to be expected. I am curious to see what you find out.

Marty

[blackbombshell95]

when i was shopping for 3400 headers their was 2 designs that i saw, 99-01 and 01 and up or sumthin like that, so you are saying that any 99+ would work????

if the headers were to bolt up, how many hours in labor would be needed?

[ikessky]

Either will bolt up to your engine. The ones that I've seen adapted were the ones made for a '99+ so I'm thinking it was the '99-'01 that you are talking about.

As far as labor hours to do the job, I don't really know. Are you still planning on swapping heads and intakes? If so, do it all together.