Hi all,
I have a L03 305 91 Firebird which I am trying to find out if this car came with dual or single exhaust. Any help is appreciated. Thanks!

 

well since the tpi was cosidered the HO and my tpi only has a single im sure that urs would be a single exhaust stock as well

 

yeap... i agree. Did your TPI has 2 tail pipes stock?

 

it was a 3" pipe goin all the way back then the muffler it spit it to become 2 tail pipes

 

I think it is just like mine.thanks

 

I have read several threads suggesting 3" cat pipe to upgrade the exhaust system.
What would be the difference b/w the 3" pipe vs let,s say, a flow master 3" cat back?
Thanks!
By the way, I am a newbie in all this...

 

All 3rd gen and 4th gen factory exhaust systems were single (with dual outlets out of the muffler). Your stock LO3 has a tiny 2.25" system and upgrading to a 3" is highly recomended. Any 3" system will do. As bad as the stock exhaust piping is, the stock cat and headers are worse. Eventually you will want to replace the stock manifolds and y-pipe with a quality set of headers.

 

Oh.. I thought stock was 3".
Did the TPI come with the same exhaust system?

 

The largest system on any 3rd gen was 2.75" and was found on L98 (350 TPI) cars and most 305 TPI cars (I think). The routing was the exact same between all cars and it "looked" the same. However, the LO3 exhaust was the worst of all stock 3rd gen systems (not 3" at all).

 

Great info! So if I find a tpi exhaust system it should fit in my lo3 with almost to none modifications? Do u think is. A good idea?

 

Its a great idea. Aftermarket systems marketed for "305 TBI" will have one of two conditions. 3" piping with a 2.25" reducer on the I-pipe (to connect to stock cat). Or they will be the same 2.25" but mandrel bent (vs. stock crimped bends) (rare but dynomax is one example). If you are not going to replace the entire system now (headers, cat and catback), get a 3" TBI system so that is bolts to your stock cat. You can cut off the reducer if you upgrade to a 3" cat and headers.

Flowmaster and Hooker have 3" systems with reducers to connect the the stock cat for your LO3 set-up.

 

That's what I had in mine. Now you meant(above) to get " 3" TPI system" right?
Thanks once again.

 

Yes, get a 3" TPI system. However, if you buy a system advertised for TPI it will not connect to your stock 305 TBI cat. You would need a reducer and extra money to make it fit. If you are only changing the cat-back I recomend getting a 3" system advertised for TBI (it will have 3" piping with a reducer and flange to connect to your stock cat.)

 

You mentioned hooker or flow master, but there are so many. Any specs or style you could suggest ? May be the one you use?