well is anything wrong with ur motor now? how many miles? is it ticking, knocking, loosing oil? if not then i would just start with a tune up. then bolt ons, advance the timing (run 93), get some gears and maybe later blower or h/c/i. or like me eventually both!
you can always rebuild it before u do all those things to freshened up. might as well get a kit with forged pistons. summit has some rebuild kits, go check them out. u can make the comp. low for the blower or run it high and spray it w/ a nice shot.
or if ya want more cubes check out these sites..
http://www.dssracing.com/
http://www.coasthigh.com/
both of those are also good for crates, few more i can think of..
world products
frpp
fox lake
keith craft