330jetstar

Im looking for stainless header flanges for both the flange that bolts to the cylinder head. As well as a flange that bolts to factory exhaust.

61Bat

I would say if you cant find any pre made look for a local shop with a cnc plasma cutter or water jet and they can scan some gaskets for you and cut whatever thickness you would need. Plenty of these shops around my area ( I work with a guy that does this on the side, I could refer you if you like) so I don't think you'd have a problem finding someone to do it for a reasonable price. Heck, have him cut a few sets and sell them to recoup your cost.

330jetstar

One website has "big block" flanges I'm assuming they're different.

joe_padavano

Assuming they are talking about Oldsmobile "big block" (and not Chevy), they are the same on every Olds V8 built from 1964-1985. Only the 1985-1990 307s with the 7A heads had differently shaped ports.

330jetstar

http://www.racemufflers.com/Oldsmobi...ges-s/2090.htm

olds 307 and 403

Those should work fine. Are you talking about the two bolt manifold hook up? I doubt anywhere would have those, those would have to be custom.

joe_padavano

If you are custom building headers, why do you want a stock manifold-style joint anyway? FYI, Walker DOES sell manifold style flares and flanges. A better choice for custom headers would be a ball and socket joint.

330jetstar

I just want to make a stainless replacement for my exhaust manifolds without chopping up my pipes.

joe_padavano

Sorry, but that sounds like a whole lot of work for very little benefit. Even "shorty" headers take up more room that cast manifolds. The individual pipes and resulting bends make what you are suggesting extremely difficult if not impossible. Look at the crappy welded tubular manifolds used on the 307s from the late 1980s. They are ugly and are the worst-flowing manifolds ever offered on an Olds motor. Cutting and welding the exhaust pipes to fit new custom-built headers will by far be the easiest part of what you propose to do.

330jetstar

Who knows I may end up cutting the pipes. If I can get my garage heated for this winter I will have a lot more time to play around.