Slant 6 Cam Upgrade
There are some good threads out there on aluminum 225 buildup.
This one and
this one are especially good, with tons of pics and descriptive text. Resist the urge to increase compression. You don't need to change the lifters, pushrods, or rockers. You may want bigger valves. See
here for cams, and see
here for slant-6 speed parts source recommendations (for and against).