Thread: 3.5" setup confirmation

Well I have SD headers in my garage now and am hoping to install them really soon here. I just have a few more questions before I order the other parts for a 3.5" pulley setup.

I hear the gaskets that come with SD headers aren't to reliable, which gaskets do you recommend?

I also hear that I might be able to re use my exhaust manifold bolts, is it a Garuntee that I can reuse them if I don't ruin them while taking them off? Should I buy new bolts?

Is the O2 extension necessary for my 99 gtp? I think I read somewhere that 04+ need them, or the other way around.

One last question. When I do install my headers, will it be ok to drive the car without it being tuned yet?

Thanks in advance :]

Reuse exhaust bots, I used the clamps the SSAC's came with, use the GM manifold gaskets for the headers. For the catback gasket get a new one from the parts store. Doesn't matter the brand. Yes the o2 is necessary or you can extend the o2's harness if your good with wiring and soldering. Don't half ass it and use butt connectors on your o2!

Gaskets that come with it are no good. I reused the manifold gaskets (head to manifold) and got a new resonator gasket from the parts store.
Reuse the exhaust bolts, unless you break them...Which shouldn't happen, but obviously use the correct size (think it's 13mm) and don't strip them.
The o2 extension is necessary, unless you splice the wires on the o2 sensor to be longer, and then heatshield them. (As ryno said, don't cheap out and use butt connectors, or you'll be pissed later on down the road)

And yes, driving on the headers untuned will be fine. Now if you delete the catalytic when you install the headers, you'll throw a code, and the car wont be happy with you, but you can get that tuned out.

Also, make sure to get Copper RTV, and some better band clamps to replace the crush style clamps they came with.

I agree with teh guys for the most part.

Reuse bolts
Reuse stock head to manifold gaskets
New catback gasket
I don't care for the clamps they give you. I prefer to get 2 2.25" and 2 3.00" clamps from frozenboost at $5 each. Much better clamps for slip fit headers. They won't put an indent like the clamps supplied. When you have to pull apart the headers it'll be much easier.

Mega Copper RTV from O'Rileys works pretty good. I used the crush style clamps because i couldn't find the band clamps locally. They work good enough, and yes the gaskets that come with the headers are sh1t! Don't use them.

I had my rear reducer from 3" to 2.25 welded on eventually because it kept blowing off under a load and would come loose.

Rtv....rtv???

Thanks for all the replies guys. I do on plan to get rid of my cat, if It's only going to set off a code, I think I can live with that for a week or so, until my PCM comes in. I was wanting to go with overkill. My exhaust doesn't have any flanges underneath, a lot of exhaust was cut off because of bottoming out too much, so pretty much CAT- straight pipe - glass pack. All welded together. Should I just have it all welded together again or should I add a flange and bolt on the headers like its meant to be?

Originally Posted by fri3dchick3n

Thanks for all the replies guys. I do on plan to get rid of my cat, if It's only going to set off a code, I think I can live with that for a week or so, until my PCM comes in. I was wanting to go with overkill. My exhaust doesn't have any flanges underneath, a lot of exhaust was cut off because of bottoming out too much, so pretty much CAT- straight pipe - glass pack. All welded together. Should I just have it all welded together again or should I add a flange and bolt on the headers like its meant to be?

Ewww.

No flange is gonna blow.

Gotta cut that apart...then drive basically open downpipe to the exhaust shop.

I can't wait for that drive haha.

How and where do you guys apply the rtv?

Just slap it on every joint/slip fit?

Yes.

Slip fit joints, and around the flat area of the v-banded DP.

i had to drive the car with open manifolds to a shop to get a bolt removed....you get some interesting looks

Well I did install my headers and daaaamn it sounds awesome. Still open down pipe at the moment. I printed out Bills easy method and followed his steps and it made everything A LOT easier. And it still took me 8 hours to do it all.

I have a question about a rubber donut gasket? Is there one inside the original downpipe? I wasnt able to find one.

I have to go back fishing on monday so the welding of a new flange will be set back a little bit late, still need to order my 02 extension and such.