The Stovebolt Site Forums The Shop Area General Truck Talk Fenton cast iron headers

Has anyone used the Fenton cast iron headers? I took the truck for its first drive today and it has a pretty bad exhaust leak. I am concidering a new exhaust system since the one on there looks to be in pretty bad shape. Has anyone used these headers? Are these the way to go or would I be better off re-condition the old manifold?

Thanks.

The Fentons can be made to fit a gmc engine, but it takes a bit of grinding. The Fentons are actually made to fit the Chevy engines. There were other cast iron manifolds available for the 228-302 gmc motors but they are rather difficult to come by.

I will be using a set of Fentons on my 302 Jimmy. If I had it to do again, I would look for a set of headers that was specifically cast for the gmc engines.

Jim Carter (and others) sells a Chevrolet and a GMC set of Fenton headers. Is the GMC set not a good fit on GMC 228-302 engines?

I put Fentons on my Chevy 261 and it still takes grinding if you're matching them up to a different intake such as an Offy. They sound great with Patrick's dual stainless steel exhaust system.

http://community.webshots.com/user/geezer

Fentons were cast up originally for Chevrolets, and then for GMC's, the right castings will fit either engine. I have Fentons on my GMC 248 and they fit fine. A little bit of grinding to port match might be needed, but that's good practice for any new manifold.

The Fentons they sell for the GMCs are actually cast for the Chevys. The only difference is where the hole is drilled to mount to the cylinder head. I say hole because there is only one per manifold. You may need to grind a bit of material off the front side too in order to get those GMC washers to have a surface to grab.

I am not trying to bash the Fenton headers, I am only trying to pass on the fact that they are not a direct bolt on replacement. It may take a couple of afternoons to get them tweaked just right. In all a very rewarding little project.

P.S. Don't forget about plumbing the manifold heat!

Seems that they need grinding regardless of whether you use them on a Chevy or GMC, especially with an Offy intake.
I'll pass along 3 things I did that helped on mine, 1- replace the 2 outside guide pins with bolts/threaded studs. This gives a little more even clamping and will help stop leaks at the outer ends of the manifolds. 2-Replace the other manifold bolts with studs. Makes for easier installation and seem to torque down better that the bolts do. 3-Forget using the original manifold clamps, they're just a pain to make work right without exsessive grinding, followed by extensive foul language when they don't fit right. I made new ones from 1/4" stainless flat stock. Much better for clamping the manifolds and they won't get on a funny angle or try to shift on you when you tighten them down.

Fentons are the best mod. ive ever done to all of my old stovebolts. Theyre money well spent.
Marty