Just did the famous 305 TBI to 350 TBI swap. I have stock 305 exhaust on it right now with a V force muffler (like flowmaster). Need to know what i should do about my exhaust manifolds.

1. Should I put on Headers? If so which ones for less than $200????

2. Can i use stock 350 manifolds? If so off which vehicle???

Thanks guys

 

Update: It's a 1992 Firebird initially a 305 tbi. Thanks!

 

If you don't have to pass emitions, then use Hedman 68470 headers. They are 1-5/8" shorties, that do have an available Y-pipe for them. The headers themselves, with just the black paint, cost around $140 or so. I don't remember what the Y-pipe cost, but it wasn't too bad either. I use these on my 350 and they are great!

 

Thanks for the great info. Appreciated! I assume i can leave the cat on or not? With headers to i have to take off the air tubes that are on my current manifolds along with the rest of the emissions stuff?

ALso, I have heard of a few who have drilled holes in their manifolds and reinstalled the air tubes, lol. Sounds pointless, but is it practical?

 

ditch the air tubes and air system and just put on those headmann shorties and a y-pipe with a nice 3" cat and 3" catback exhaust of your choice. Also jump on the chicago board and say hello to your local members.

 

xpndbl3


Thanks man! lol. Will join the Chicago group. How do i do that????

 

The Hedman headers don't have AIR tubes. Thats why I said "if you don't have to pass emitions".... because they wont, because of the lack of AIR tubes

They are a VERY good setup IMO, especially for the price, but there is one small mod you should do to get the most out of the system when you get it. The Y-pipe sends the two pipes off the headers into a collector that goes into a 2.5" pipe, which isn't very good for performance. The cure is easy though. Right in the middle of the "collector" on the Y-pipe, cut it off. Then you will have a nice 3" outlet to hook your exhaust system up to. Any exhaust shop should be able to make you a 3" pipe to go in place of the 2.5" peice, and weld it to your Y-pipe, for very little. Thats what I did.

If you decide you don't want to cut the Y-pipe, you may lose a few HP, but not much (of course, this depends on how hot the engine is too). No big deal