X2 with AP 72.
You can get a complete stroker kit to pump it up to 347 cubes. Very nice.
Also GT 40 heads can be had for a little legwork and some change $$
Just find a 96-97 explorer with a 5.0 liter in it. Grab Dem heads
Plent of good 303 grinds right from ford motorsports for a cam.
Some of them alabama boys making gobs of horsepower on Passtime with - ahem - "mostly stock" 302 s
Welcome to HR . hang around , do some reading , ask some questions ...build something cool.