[1blackbb66]

Sal,
I had a chance to go and talk to my dyno guy tonight and he had many thoughts on this, some in line with what you are saying. The real problem often appears to be threefold. First due to space and many times aesthetics, is that the primaries are of unequal length and how they merge into the collector area is not optimum. He says there needs to be a stinger or cone in the collector area to aid in maitaining flow velocity as well as taking advantage of pulse scavanging. Some manufactures address this but most do not. Two...no crossover pipe to balance the exhaust. Third, and probably the worst, is very restrictive mufflers in order to reduce sound levals. With such limited space and again, aesthitics, not enough room to have a good flow path through the muffler that maintains velocity and reduces sound levals.
My engine builder says the way he put my 460 together it should be making around 475 HP. It was never dynoed so I have no confirmation of this but on the chassis dyno we only got 283 to the tire. Needless to say I was quite dissapointed. I have compiled a lot of good information and I will be addressing the side pipe issue.
Thanks for the info.

Ray