Ok from what I've read it looks like the Pacesetter headers for the 2.8 will fit in my 1991 firebird with the 3.1. Is this true? Has any one here done this? If so, what are some good tips on installing them, is it easy to do myself or have a shop do it, any problems you ran into with them, and what would be some of the best cats and cat back sytems to bolt up to it. thanks

Soak the old bolts in PB Blaster overnight so that you don't break them. You will have to loose your AIR pump, you may need a shorter belt. slip the headers on with Felpro gaskets, not the cheap ones they send with them and get a Dynomax cat-back, it has all new piping ar 2.5" and it doesn't sound too bad. Also I would get a highflow cat off of ebay for pretty cheap and call it a day.

I called pacesetter and asked them the same thing, they said it would not work on my 3.1, but some people have told me that it can, I havn't bought them for the simple fact that I'm not sure which is the correct answer.

They will bolt up to a 3.1 but you have to remove the smog pump...

Pace is saying that to cover there ***. I installed the very first set on a 3.4 in a 1991 model.

A few weeks ago, I posted my typed up directions on how to bolt them that use to be on my website that I closed.


http://www.thirdgen.org/techboard/v6...t=#post3540528 (pacesetter headers)

Problem is if you live in a state where you need emissions testing you won't be able to pass it w/o the AIR pump

You will not loose your smog pump. You have to take it off to get the header in there and then you put it back on. You do have to remove the tubes on the back of the smog pump. There is no other way to route the belt. Ive seen me do it, and the car is in the garage.

I thought the smog tube routing was different for the 2.8 and 3.1. I thought that the 2.8 had one tube for every exhaust port and the 3.1 had one tube.

The 2.8 doesn't have any kind of tubes comming from the exhaust. There is the EGR valve that has one big tube from the valve to the intake.

The tubes that inject the air, from the smog pump, into the manifolds. Mabye Im thinking of the V8s.

You are thinking of the V8s. They have those seperate small tubing for the AIR injection.

Nope...the 2.8L has an Air Pump with the tubes that go ino the driver side manifold.

thanks alot guys, it sounds like it will be a fun little project.

Mine didn't. Manifolds or headers.

They will fit with some minor alterations. I installed a set on to my '91 firebird last year without too many problems. You should be able to do them yourself with some sockets and short wrenches. Both sides will go in from the top. The driver's side, you will have to take off the power steering pump and if I remember right one of the 2 back bolts either doesn't go in or doesn't tighten all the way when reinstalling the pump. On the passenger's side, you will have to pull the smog pump and slide it in from the front. The back half of the smog pump will be in the way, so just unbolt it and take it off. You need to have the pulley there because of the serpentine belt routing so that much will have to stay. The back bracket of the alternator will have to go as well. I can get pics later if you need them.

fictmich, sounds like you did alot of extra work. Only thing I removed was an alternator.

Maybe your setup was different? The power steering pump was mounted to the exhaust manifold so that had to move out of the way, along with the alternator bracket. Then the back of the smog pump was in the way of the primary for #1, didn't have a plug in for it anyway in the headers.

I had to pull the power steering pump too. It has a bracket on the back that attaches to where one of the header bolts is.

Not true. I removed ALL of the smog equipment; smog pump, cat, EGR, etc. from my 2.8 and passed WA's sniffer test easily. Luckily they don't do visual inspections up here.

ok since the 3.1 is on the subject i have a 92 with a 3.1 that i wrecked a few months back and i have a 92 S10 with a 2.8 blown. can the 3.1 fit in the S10 without much modifying being done???

pretty much a direct bolt in, just use the 2.8L accessories (bracketry, manifolds, etc.)

For a simple answer, yes, the 2.8l and 3.1l engines are identical for all intents and purposes, the 3.1l is merely a stroked 2.8. From what I read skimming through the posts, how easy or complicated it will be is going to depend on year, and transmission.

Resurrecting an old thread here. I just ordered a set of Pacesetter Headers. P/N 70-1206. These supposedly bolt-on to the 2.8L V6 Engine, I have a 3.1 V6, and as was already stated the engines are identical to a large degree. With that being said, will these headers bolt on with little to no altercations, or was the purchase more trouble than what its worth.

Also for a backstory, I am, or at least starting a budget rebuild of my 3.1 V6. While so many people just buy these cars and throw a 350/383 in them, I am choosing to keep my RS as original as possible, while squeezing out all performance that I can. I estimate to increase the est. 140 hp to at least 235 once completed.

As long as they are for a 3rd gen v6 they should bolt up just fine.
Also just fyi, hitting 235 is not likely without going hybrid or boost. Or a pretty radical NA build that wouldn't be very street friendly or cost effective.

I dont know a ton about modding these engine to the extreme, But i do know that i massivly ported the heads, cam, and stuff like that and im sure i didnt end up with more then 155-160hp crank total, if i was really lucky.

Am91Camaro_rs did a good job at making a fast N/A car that ran low 15's and even 14's in the quarter mile, but that was with some high comp ratio....10.?:1 i think, large stall conv. So its possible to make 200hp im sure but 235 is a stretch! Exspecially if your on any sort of budget!! Im hoping for those numbers(235Hp) with a turbo

Alright sweet thanks. I had done some research before hand, and taken some measurements. But I wasn't too sure, and figured I'd ask.

I suppose 235 is pretty optimistic. I was planning on tearing the engine out and sending it out to a local machine shop to have it torn down and checked out. I was looking at doing a 3x00 top end swap, and switching out the plenums, along with the headers and a magnaflow exhaust.

Just fyi, if you go hybrid, the headers won't work, not unless you can modify them to anyway, 3x00 heads use D shaped exhaust ports, I think its a different size as well.

1. 3x00 bolt pattern is wider. Header flanges will need to be modified.
2. 3x00 pretty much requires use of headers with 1 5/8" primaries (measured the ports). Pacesetters have 1 1/2" primaries.

The ONLY headers I can see working on a 3x00 would be RKSport 3.4 1993-95 headers (1 5/8 primaries and $200 more), but I can't get anyone to confirm if they need to be modified to work in a thirdgen chassis. As soon as I can get an answer, I'm going with one or the other (3100 hybrid in the garage only needing pushrods and rockers, which will be bought within the next couple weeks, waiting for the body to be finished).

the bolt spacing is a little larger vertically however you can just oval the holes and they'll bolt up fine.

The issue is that headers for gen 1 heads are usually 1.5" primaries, there will be a little overlap of the corners when used on gen 3 heads. This shouldn't stop you though, I've used the very same combo on a set of longtubes (gen 1 flanges with 1.5" primaries) that went onto a cammed, P&P'd 3400 and it's been daily driven like that for several years with no issues.


It put down about 245 WHP with a 5 speed.

You have any issues with exhaust leaks at the heads?

Personally if it were me, I would probably get the header flange piece from wot tech, cut the flanges off the pacesetters and graft the wot tech flange on, probably the easiest way to go about it, obviously would take a little more work than that getting the pipes to fit the flange right, but easier than starting from scratch and figuring out the routing and all that crap at least.

The wot-tech D shaping tool is for 1 5/8" primaries (Mars still has mine.. lol)

If you wanted it to be better then i'd cut a little over an inch back past the old flange, D shape the ends of 6, 2" pieces of 1 5/8" tubing, slide them in the new flanges and then slide the pacesetters into the bigger pipes. Weld it all up solid and have them re-coated. Not truly a stepped tube header but the transition would be smoother.


Here are the longtubes that i built for a friends car..



and on the car (94 Cavalier Z24)




Never any leaks, we used standard GM MLS exhaust gaskets for the 3x00. He's probably put 30K+ miles on the car since we installed them. The coating isn't that shiny anymore though.. haha

More or less what I had going on in my mind of what I would do.

All I can say is WOW