TAC Tech => Mechanical => Topic started by: BlueBaron762x39 on April 11, 2021, 07:23:27 PM

Title: Olds 403 Stock Exhaust
Post by: BlueBaron762x39 on April 11, 2021, 07:23:27 PM
Is there a stock replacement exhaust set available for the 1979 Trans Am with the Olds 403?  I just want to replace the old exhaust with the correct system it originally came with.
Title: Re: Olds 403 Stock Exhaust
Post by: Wallington on April 11, 2021, 08:36:34 PM
I believe Walker did, once. You still have cast exhaust manifolds with cross-over and want single pipe with cat option?
Title: Re: Olds 403 Stock Exhaust
Post by: olds403 on April 11, 2021, 10:12:40 PM
You cannot get the y pipe before and after the conventor.  Long gone. 
Title: Re: Olds 403 Stock Exhaust
Post by: Warren Seale on April 12, 2021, 08:53:41 AM
A good compromise is to use the Thornton small block manifolds if you are going to have true dual exhaust.  This will eliminate the stupid crossover port on the right side manifold.  The manifolds have the original appearance but have a slightly larger passage.

 https://www.thorntonmusclecars.com/product-page/thornton-s-350-jr-exhaust-manifolds
Title: Re: Olds 403 Stock Exhaust
Post by: Wallington on April 21, 2021, 05:59:44 AM
https://www.ebay.com/itm/NOS-1977-78-79-80-81-Pontiac-Trans-Am-Formula-Tailpipes-w-Chromed-Tips-547824-/313075773184
Title: Re: Olds 403 Stock Exhaust
Post by: Warren Seale on April 21, 2021, 06:51:38 AM
https://www.ebay.com/itm/NOS-1977-78-79-80-81-Pontiac-Trans-Am-Formula-Tailpipes-w-Chromed-Tips-547824-/313075773184

Pretty costly.  I'm not sure what an NOS exhaust gets you.  The pipes in those days were not aluminized or stainless steel.  They tended to dissolve it short order.  The chrome on the tips appear to have pitting.  I think reproduction pipes with modern materials would be a better choice.
Title: Re: Olds 403 Stock Exhaust
Post by: Wallington on April 21, 2021, 07:11:38 AM
My message with ad didn't appear, but you covered what it said. Along with saying this one has the second splitter open, some were dummy outlets.
Title: Re: Olds 403 Stock Exhaust
Post by: roadking77 on April 21, 2021, 11:55:34 AM
NOS is nice, but I dont think I spent much more than that on the entire pypes settup for my 77.
Theres as guy in NY I think (sorry for the lack of info but I am sure its out there) that makes a correct exhaust. Guys that want 'concours' quality use this kind of thing. I have heard they are quite pricey as well.  I have read about him on the PY site. Someone there may have his name and number if you want exact.