Best flowing exhaust manifolds

I race an enduro circut where the rules specify stock exhaust manifold.  What are the best flowing exhaust manifolds that I can get.  I have access to some 95 formula TA exhaust manifolds.  Thanks  

Stock manifolds dont flow well at all thats why they get tossed however in your situation I would use whats reffered to as RAM HORN manifolds  

I run a 84 regal metric body w/ a 383 Patriot heads and a hogged out cast iron bowtie intake.  The rams head will not fit.  Everything has to be "cast iron stock appearing"  thanks  

you can use aftermarket heads but not headers? WTF   Are you saying they have to be stock for that type of car?  

The rules state that you have to have a cast iron intake and exhaust manifolds that are "stock appearing".  Thats why i have a hogged out bowtie intake matched to the heads.  I know that a lot of wissota racers use early 90's 5.0 PU manifolds that they say flow the best.  who knows?  I figured that the 95 firebird formula manifolds would flow pretty good because they look a lot like headers.  thanks  

Can you post a pic of the manifolds?  

How do i post a pic?  

I've always replaced my heads with headers. but i have always been curious if you could grind out the inside of the manifolds. and actually port them somehow. My guess is it would prolly ruin the integrity of the manifold and crack. Just curious.  

I've PORTED several manifolds[intake and exhaust] for certain classes in racing and have had no problems with any of them cracking.  

jon, if your interested its basicly doing a gasket match port job. You'll find that you dont have to remove as much material as you think.  

You learn something new everyday. I might do that someday just to do it. I have loads of old exhaust manifolds that i took off just sitting around.  

jon, I think you have yourself some practice pieces to learn on.

Jake  

since you have plenty the first thing to do is cut a manifold inhalf at the port so you can see how thick it is. This gives you an idea of how much room you have to play with. Put on the protective gear and kill a saturday learning something new.  

Well Sunday would work better lol. How thick do you recommend to keep the walls?  

I've cut them down as thin as 1/4" with no problems but they are normally tossed at the end of every race season. Theres not alot of material to remove from the manifold for a good portmatch. If you use stock or small port exhaust gaskets you want have to grind at all. Sunday is normally family day for me so I have to get all my work done in 6 days. LOL