hello .. newbie here.. i have a 1979 pontiac trans am with the 403 olds motor. i have purchased a 2.5 in stainless pypes exhaust system to install myself.. this system is a true dual exhaust, not a factory replacement. the system is only from transmission crossmember back.. NO company sells downpipes to complete the system.. the exhaust manifolds are stock and i dont wish to use headers.. the drivers manifold has a 2 in dump and the pass. side manifold is a 2.5 in dump. the pass. side already has been plugged where the original crosspipe from the drivers side once connected...i have looked into the thornton's 350 JR exhaust maniflolds that will look stock and fix my dump size problem, correcting to a even 2.25 in dump on both sides..but it will cost me about 350.00 and i will still have to bump a 2.25 in stainless downpipe up to a 2.5.. or should i just leave the stock manifolds on and have a 2.5 in downpipe made for the pass. side, and a 2 in to 2.5 in downpipe made somehow on the drivers side and save the money i would of spent on the thornton's exhaust manifolds????? any help on this subject will help me alot thanks

 

As with most 'newbees', you refrain from giving us a location, [which I can't understand] so It's kinda hard to give you a place that might do a good job, at a reasonable price!
Those pipes will have to be custom made to your application, by someone who works with SS!
I've two shops in the Chicago suburbs, one way NW, the other SW that do stainless exclusivly - maybe someone in your area could 'turn you on' to a local shop, IF WE KNEW WHERE YOU WERE!!!

 

If it was my car I'd go with the Thornton manifolds. I never liked the idea of having to run a block off plate. You also have the advantage of a divided center port which I believe your stock ones don't have.
If it helps they are $300 with shipping on EBay.
http://www.ebay.com/itm/65-75-Cutlas...item2568ddecb3

 

sorry rickman i live in dayton ohio

 

thanks for the link and your reply