I think I'm gonna go w/the s orig. type exhaust setup on my 390GT FB. However, down the line I'll prob. add CJ exhaust, heads and intake. I was wondering if I can get the 2.25 CJ exhaust - h -pipe and all and what I will need to do to match it up to the stock 390GT exhaust manifolds? My friend said I will just need some deals (the name of them escapes me now!!) that make the diameter of the H-pipe smaller so it will mate to the smaller 390GT manifolds. Does this make sense?
I would suggest getting some CJ exhaust manifolds. The exhaust is only as good as the smallest opening. If you use the 2" 390GT manifolds, you'll be wasting your time putting the larger pipes all the way back.
I'll eventually get the CJ manifolds ($$ right now doesn't allow it!). I was trying to think of a way to save replacing the exhaust again when I do get the CJ parts a yr or so from now. Prob. just cheaper in the long run to get the 2" exhaust now. Prob. would not make too much sense now bolting up CJ exhaust to 390GT heads. Really need the while 3 pieces - the heads, exhaust and intake (which I have...)
The cobra jet exhaust manifolds will bolt up to 390 gt heads but you will have to relocate one hole on both heads but the cobra jet manifolds will flow better than the 390's and if you do put on cj heads later everything will bolt right up.
thanks for the responses. I do know what CJ manifolds look like - I had them along w/CJ heads and intake on my 390GT '68 coupe. I guess I'll just go with the 390GT dtock exhaust setup and when the time comes down the line I'l lupgrade to the CJ setup when I put the CJ parts on.