at your profile I don't see any exhaust manifold mods. That will become the cork in the system. Highly suggest (as mentioned previously) you consider Greg D.'s inconel manifolds (I've bought my set for my sport 500 powered car engine rebuild. The dyno charts are available in search). If not the inconels, then make sure you have someone familiar with porting the stock ones, do that for you. My $.02. Good luck in whatever you choose, Mark