Just was wondering how many other people have done this...I don't have duals on my thirdgens, but I "made way" for my girlfriends camaro exhaust system by smashing in the rear passenger side hump and putting the 3inch hooker single in, single out muffler there with a turndown. I could see how a duals system could EASILY be down by just bashing in the rear driver side seat hump. I was contemplating buying two mufflers and full length headers for my firebird and going with a dual 3inch X pipe system. My buddy has down this on his thirdgen and he gained BIG time power with the same motor setup I've got. The metal there is REALLY easy to push in, just takes like 5 minutes with a good size beater stick. I discovered this because my buddy said you had to cut holes under the rear seat buckets, but since I didn't want to cut any holes I decided to see how hard it would be to dent the metal up, and its REALLY easy. Unless you don't like beating on your car The bashed in humps have absolutely no effect on interior appearance or rear passenger "comfort", even I don't believe in carrying more than 1 other person in my thirdgens..but.....
Chris

 

Forgot to add....the bashed in place is where I put the aerochamber muffler, fits like a glove. car NEVER bottoms out. Has 50 series tires

 

yeah i noticed that but i dont know about beating on floor pans with a sledge

 

Sure, theres enough here that have done it already. I don't know about doing that either though.

 

Especially on a unitized-body vehicle. (Note to self: check floorpans thoroughly when buying a used thirdgen)

 

chris, you have mail.

 

I have a 89 t/a that I am putting together. I have a 350 and a 400,
but I am not sure which engine I am going to do because of cost. the 350
needs just a basic rebuild, rings/bearings, etc. The 400 needs pistons, and
if I build it I want to put good rods on it, so the cost of the 400 will be
considerably higher. With either engine, I have a set of hooker long tubes I
am going to put on it. I haven't decided if I am going to go with true duals
or single 3.5 or 4. I have seen true duals on a formula in bowling green
before and it looked really good. he said he didn't have any problems with
it, and it sounded better than any single exhaust set up would. The mufflex
system is way way to expensive for me. I was looking at my car the other
night where the rear seats are, and how if I beat those up, a flowmaster
would fit well there. I have attached a pic of how I think I am going to do
mine, it seems the best route so far. What have you decided to do? Also,
those are some good times out of your 355, If I build my 350, that's the cam
I want, and I have a set of ported 461 vette heads that will go on it, so my
combination would be similar to yours, except I will have a 700R4 with 3.42
gears. Keep me updated on how it goes. Thanks

 

heres the pic

 

a little too close to the driveshaft for comfort in my humble opinion. the torque arms close enough as it is...

 

ttt

 

A freind of mine has true duals on his 91 RS. He ran his exhaust like the newer vettes with the mufflers at the end of the pipe.
Looks pretty sweet !

 

why not just ovalize the pipe for a better stance. it would certainly help with the clearance issues. just wonder where and how much it would cost for oval pipe

 

i have never seen oval pipe, i hate to see how much it is, maybe i could just drive over some regular pipe, that might work, lol

 

doesnt spintech sell oval pipe

 

that pic is not a 3rd gen

just thought I would point that out.

 

Yeah that looks more like a 4th gen. The frame around the transmission is different, you wouldn't be able to route it exactly like that on a 3rd gen.