[Toasted Hydes]

Hey Guys,

I have a few questions that I was hoping you all could help me out with. This past June at the All GM Nationals in Carlisle I bought a Pypes Exhaust system for my 1979 Trans Am with an Olds 403. I was talking to the guy at the Pypes stand and he said that they did not make a down pipe for the 403, that I could go and get headers or get a down pipe made. Does anyone have headers on a 403? If so, how loud is it? Also, has anyone had a downpipe made for it? What do you guys think i should do? Thanks.

[Laguna454s3]

I would keep the manifolds and have a local exhaust shop make up the downpipes.

The 75/76 455 Olds used a dual outlet passenger side manifold. There was a crossover pipe from the drivers side manifold that connected to the pass side manifold and then exited into a single downpipe.

I'm not sure of the configuration for the 79 403.

I'll be doing a dual 2.25" setup on my 75 455 Hurst Olds with a shop bent exhaust. I have a single outlet pass side manifold to put on and will run 2 downpipes eliminating the need to cap off the other manifold outlet.

John

[gto4evr]

capping the manifold isn't that big of a deal. I have 68 olds cutlass, bought stock duals for it and just took the old crossover pipe cut one side off about 2 inches down and welded a plug on the pipe. The outlet on a two hole passenger manifold is in the same location as a single hole manifold so no custom exhaust was needed. Down pipes are something any shop could make up for you. As far as header noise, it depends on your mufflers. I've got headers on a 65 Belvedere 383 that you'd swear was a stock single exhaust system for how quiet it runs. Stay with the manifolds, they don't rust through in 5 yrs!