[Argess]

Yes, the manifold has an exhaust cross-over passage. I have it blocked off using gaskets without those ports.

And yes again, I thought it was probably for tall port heads which I assume are the high riser ones.

I would have thought the mismatch would have affected high rpm performance more than low. It's only between idle and 2000 rpm where I think there is power yet to be unleashed.

I've tried researching this manifold and there's not much on it. Most people pooh-pooh it, but in reality have never tried it. I did find 2 posts on other forums where the contributor used it and both of them liked it. If the manifold really is the problem, I suspect both of those guys had it in an automatic tranny vehicle where the engine could get up a bit in revs before the torque convertor started to load up.

I've also read two posts in another forum where guys with the Fireball cam (like I have) both said that their engines "came alive" with the cam advanced 4 degrees, but wern't specific about "how it came alive".

Despite the fact a new manifold might be pricey and advancing the cam costs nothing but elbow grease and some new gaskets, I'd much rather change the manifold.....a lot easier. But as I mentioned before, I was hoping someone else who had tried the manifold could confirm or deny they had similiar problems as after all, it would be disspointing to change the manifold and not find a significant improvement.

Then there's the fact I have a very driveable car with more power than I can get to the pavement from 2500 rpm up. Right now, if I get it just over 2000 rpm in 2nd, I can only give it 1/3 to 1/2 throttle (depending how hot it is ooutside) before I worry about losing traction.

But it would be nice to let out a little tire squeal without much effort.....