[bobcowan]

First off, have you had the car on the dyno?

There's a few reasons for this. Is the engine performing up to it's potential? You may find an underlying problem that needs to be addressed. Or you may find that it's performing as designed, but you just need more power.

Second, have you done a compression test? If your cylinder pressures are all low, then it could be you have not enough compression. Or you might be down one cylinder.

IMO, you shouldn't make any changesyet