Chevy & GMC Vans

I have been searching pages and pages of old site to try to find anyone who has done a later yr swap of the vortec 5.7L.I found on http://WWW.car-part.com the 1996 to 2000 version stock headers are listed as different than the 1995 and earlier ones.The thing I wanted to know is which 1996 to 2000 stock cast iron headers fit into A Astro and also fit the stock Y pipe?.I am dead set against tube headers.

Thanks,

Gary

You need to learn a bit more about the Vortec 5.7. One thing is that they do not use exhuast gas through the intake manifold for the EGR. It is plumbed through the drivers exhuast manifold. Hence, different manifolds. Lots of info out there on it.

Then what your lookin for are exhaust manifolds =). Chevy, to my knowdlge, has never put headers, from the factory on any of thier cars. But if I rember right a few people posted on the old board that the full size truck manifolds worked best. I cant be sure of this though.

lockdoc wrote:You need to learn a bit more about the Vortec 5.7. One thing is that they do not use exhuast gas through the intake manifold for the EGR. It is plumbed through the drivers exhuast manifold. Hence, different manifolds. Lots of info out there on it.

Thanks for chiming in Lockdoc.No doubt about it.I am looking almost every day for info.Going to a bookstore in Roch to buy one of the"how to books" on vortec's.Lots different than what I am use to.Thanks for the tip on the manifolds.

Hotroder383 wrote:Then what your lookin for are exhaust manifolds =). Chevy, to my knowdlge, has never put headers, from the factory on any of thier cars. But if I rember right a few people posted on the old board that the full size truck manifolds worked best. I cant be sure of this though.

I believe your are right Hotroder383.The real question is if I can find one from a 1996 to 1999 full size truck that is a vortec 5.7 cast iron stock manifold to fit into a Astro.

Thank you for your replies.

I have used manifolds from many different years on 2wd Astro V8s. So far the only ones I tried that did not fit were the old ram horn ones. So basically any manifold SBC that dumps near the rear will work in the 2wd. Vortec heads have the same exhaust port spacing as all the SBC heads. What I have noticed (when shoe horning engines into very tight spaces) is that some heads (aftermarket) have the ports at different heights (same spacing though). This height difference should not affect a 2wd swap application as there is a lot more space.

Rockwerx wrote:I have used manifolds from many different years on 2wd Astro V8s. So far the only ones I tried that did not fit were the old ram horn ones. So basically any manifold SBC that dumps near the rear will work in the 2wd. Vortec heads have the same exhaust port spacing as all the SBC heads. What I have noticed (when shoe horning engines into very tight spaces) is that some heads (aftermarket) have the ports at different heights (same spacing though). This height difference should not affect a 2wd swap application as there is a lot more space.

Thanks Rocky.I was thinking there is alot of space on 2wd drives too.Just wanted to confirm it with someone here.

I used some manifolds off an 81 full size van for my 85 Astro V8. They fit well and are nice and quiet...the quietest V8 I own actually. There are better manifolds from what I have read. Look for some with the largest outlet possible. I have seen some manifolds with a 2 inch outlet...most manifolds have a smaller outlet. Some of them you can hog out with a die grinder to gain some air flow. Good luck!