I am replacing my stock manifolds are the Imco powerflow manifolds worth the extra 200 bucks over the stainless marine on a 454mag. Teague custom marine says they make more power but i am not sure.

Stick with Stainless Marine. They have a better design where the riser meets the manifold. I guarantee you that you would never be able to detect any performance differance between the two manifolds, one way or the other.
If you want to make the most power buy real tube headers, Lightning, CMI, etc.

Hey Formula I lost your e-mail did you get it on your boat yet? your my tech support 4 when i put mine on

FYI, There's a used set of Stainless Marine exhaust in the classifeds.

might look into the new Dana products manifolds they have out,

TOM R

I just found a set of CMIs and am in the process of getting them mounted on my 502 EFI -- but both times I have had any contact with TEague Custom Marine - they immediately "run down" the CMIs as not performing well with the EFI and bragging up the IMCO.

Every comparison I've ever read, has always shown CMIs with superior #s to IMCOs.

WHAT GIVES????

MAV

One fact that is not apparent to the naked eye is the construction of our manifolds. Every other major maufacturer molds their aluminum manifolds the same way. They make a mold with all sorts of hidden passages and lost cores, etc, and mold it. It is totally uninspectible internally, and essentially the same thickness inside and out. It might be perfect, or it might not be so perfect. Guess who is going to find out! Our manifolds are molded simply, like the manifold on your truck or car. No hidden passages, easy to inspect. We then form the cooling jackets using a deep-draw process, and install them "on the half-shell". We add the water fittings, heat them up in an oven to 500 degrees, and weld them while they are hot. They cool slowly, so as not to build up stresses. You end up with: A perfect manifold every time. A manifold that is two and a half times as thick in the inside vs. the outside. A manifold that promises to pee in your bilge when it dies, and NOT in your engine. (In 15 years, we have yet to hear of an engine ruined by the failure of our manifold). A dry joint between the manifold and the riser. People who do otherwise do not have your best interest at heart. We invented the 5 year warranty on manifolds, after many years of good experience.

What manifold is that Brownie?

Stainless Marine, of course!