Is your truck TBI?
My old 91 burb ran awesome with stock manifolds, modified stock y pipe(believe it had a Flowmaster collector), 3” from the y pipe back, no cat, and a Flowmaster 40. If I were to do it again I would do a high flow cat. Virgin exhaust stinks and no one enjoys breathing it.
My current truck has the original cat and y pipe. 3” exhaust from the cat back. I’ll be having a high flow cat and a new y pipe collector installed soon. I’m sure the original cat is probably well past it’s prime. Heated O2 sensor will follow.
Headers on a stock TBI engine are a waste of money. New manifolds are cheap if yours are cracked or warped. Cheap headers won’t seal and the extra heat in your engine bay isn’t worth it. Expensive headers with thick flanges will seal but there will be no performance benefit and you still get stuck with the higher engine bay temps. Again this is for TBI. I have no experience with Vortec trucks and they may significantly benefit from headers.
My old 91 burb ran awesome with stock manifolds, modified stock y pipe(believe it had a Flowmaster collector), 3” from the y pipe back, no cat, and a Flowmaster 40. If I were to do it again I would do a high flow cat. Virgin exhaust stinks and no one enjoys breathing it.
My current truck has the original cat and y pipe. 3” exhaust from the cat back. I’ll be having a high flow cat and a new y pipe collector installed soon. I’m sure the original cat is probably well past it’s prime. Heated O2 sensor will follow.
Headers on a stock TBI engine are a waste of money. New manifolds are cheap if yours are cracked or warped. Cheap headers won’t seal and the extra heat in your engine bay isn’t worth it. Expensive headers with thick flanges will seal but there will be no performance benefit and you still get stuck with the higher engine bay temps. Again this is for TBI. I have no experience with Vortec trucks and they may significantly benefit from headers.
