You should see gains from the s2k manifold and other basic bolt-ons, as for the amount of increase I have no idea. To gain the full benefits of this manifold you would want hondata or uberdata a good tune and a set of cams&gears wouldn't hurt either.

The HCP mounts are supposed to place the motor father back than the HASport mounts. With this being said you may need to move some of the items on your firewall (brake prop valve, fuel filter, etc) or perhaps you'll have enough room. I cannot say for sure as I do not own one of these manifolds. If you search HT I'm sure someone either has it or has tried it.

-Mike