Hey guys, I've searched and searched and have not gotten a firm answer to my exhaust questions. I just picked up a 1992 RS LO3 totally stock. It has 68K on it and it needs exhaust because of a hole somewhere in the system and its rusted out pretty bad. I want to do exhaust from headers all the way back to the tips. I have already decided on a Flowmaster American Thunder Cat-back, and I'll most likely get a Catco Highflow Cat, but its the headers and y-pipe that have me all undecided. I know that everyone says to get headers with 3" collectors and what not, but the only true bolt on headers are the Edelbrock TES for TBI and they only have 2 1/4". I really think it is unnecessary to put a full 3" exhaust on a 305, I think you would see more of a benefit with a 2.5" exhaust. Does anyone have any DYNO proven stats that the TES TBI headers hurt the 305 TBI? Anyone have any DYNO proven stats that the 3" is better than 2 1/2" on a 305TBI? I just need some real stats to see if I'll be hurting myself by getting the TES TBI headers through a 2.5" catco into the American thunder system. Thanks!

 

Thanks a lot guys! Geeze, I guess there is no proof or answer to my question eh?

 

Definitely go with Hooker headers !

 

Since you're changing all the exhaust, do it right. Get the parts for '86-'90 TPI single cat application. I know, I know, you don't have TPI. But, that doesn't keep the exhaust parts from working. The extra capacity of the TPI-type exhaust will be noticeable, and will support any other performance upgrades you might consider in the future.

 

The edelbrock headers that you are talking about are made to be a direct replacment for the stock manifolds. meaning the y-pipe will hook up to the stock cat (that is why it is so small) and it has that thermac sleeve on it. You do not need either of these if you are going with a a larger cat and have an open air element. Just do what five7kid mentioned. Buy A complete system for a 350 TPI car and everything will work out great.