What companies offer headers for a Poncho 400 in a G-body? Seems like they're hard to find, unless the up-to-'77 headers fit G-Bodies also. It also seems that headers can ONLY be used with a dual hump or modified crossmember...are "shorty" headers available for this combo, or are there some great flowing manifolds available?

What companies offer headers for a Poncho 400 in a G-body? Seems like they're hard to find, unless the up-to-'77 headers fit G-Bodies also. It also seems that headers can ONLY be used with a dual hump or modified crossmember...are "shorty" headers available for this combo, or are there some great flowing manifolds available?

The ram air style manifolds flow as well or a wee bit better than the "shorty" style headers that are available.Two part #s of shorty style headers are available from hedman the numbers areas follows, # 28164 is listed as fitting 70-81 firebirds and #28170 is listed as fitting 64-72 lemans/gto, as far as which will fit the g-body better I would probably bet my money on the #28170 myself though I have no way to prove for sure(just a guess). Both headers retail in the 225.00-250.00 range which makes the repo ram air manifolds the best sure fit option in my book as they are available in the 300.00 dollar area.And possibly someone with hands on experience can tell you if there is a decent low cost full length header that will fit that is for another application.

As far as the crossmember issue it is probably best to use the available aftermarket double hump crossmember as most methods I've seen for modifying the exhaust/crossmember are "make-do" at best and at worst create a weaker crossmember or poor flowing exhaust.

The old 3 tube headers will fit also. I just notched the crossmember and added u-shaped materal for support. Worked for me.

ufo,

I know what you mean by "3 tube" header (single center pipe), but can you tell me what manufacturers, and fitments would fit on a 78 G-body? I mean like, if one listed for a 73-77 Lemans/GTO/Grand Prix (A-body?) 400 would fit a 78 G-body with a 400. If so: what, if any, hammer modification would the headers need?

I think the 3 tube were all universal fit. Would fit A and F bodies. I had several sets over the years and they all were pretty much the same. No banging or beating was required.

Ask on the "parts Wanted" board. Im sure someone has a set to let go of for cheap that you could try.

<http://gallery.bcentral.com/GID47169...aders.aspx>

This shows Indian Adventures' set for G-bodies. Doesn't PYPES/PY offer a custom mount to fit dual exhaust on these cars so you can now run these longer tube headers easier? This address shows a photo of one brand they must have something to do with.

http://www.pypesexhaust.com/gallery09.html

I used 68-72 A body headers in my 83 Grand Prix with a 400. These same headers were used in a 69 Lemans and a 74 Grand Prix. Even though tey were made for the A Body, they fit the 83 G Body the best. Also modified them to fit in my 62 Grand Prix until I bought headers from Mad Dog Headers.

Thanks so much!! That info I can definitely use. I'm sure old A-body full length headers can be found FAR cheaper than $550 a set, lol. Heck, it'll be like getting the dual crossmember for free!

I'm in the same boat. I have an 82 gp with a 400 poncho, did the a body headers fit and how was a/c box clearance?

About the Hedman shorties - in my 79 GP, I am using the 28164's. The pass. side slid right in. The drivers side header would not clear the frame. I cut off the collector as close to the tubes as I could get. Then I welded on a new collector made from 3" tubing that I cut at an (30 degree, I think) angle. After that, and a bit of massaging, it fit.

I fabricated my down pipes from 3" Summit U-bends, and the ground clearance is excellent, which is the whole reason I decided to go with shorty headers in the first place.

So, for future reference, the 28164's are NOT a direct fit on the drivers side. Perhaps the 28170's would fit better, but I can't say. If someone else has tried them, please let us know. I'm curious.

79gp400 I pm'd you..