If the Sportsman II heads are stock out of the box, you will come up a bit short of your power goals. these heads need to be fully ported to realize their full potential. Did you flow test the heads? You want up around 260++cfm.
Once properly ported they make very very good power. They have 600hp potential when done right.
The RPM manifold is a very good intake, but with a 4500 to 6500+ rpm range you can go to a race single plane like the Vic JR or Professional products Hurricane and make more power.
The motor (with your healthy cam) will want to rev and you may want more gear (4.56) and 6800-7000rpm thru the traps. In excess of 500hp++ is well within reach with these changes.
Last edited by F-BIRD'88; 08-24-2008 at 06:20 PM.