If you have a 96 & later Mustang with a modular motor buy the Pro Mod long block with the fully ported PI heads not a 331. If you have a earlier Mustang pre 96 then the 331 would work fine. Their motors are made from quality parts and when you get the Pro Mod setup you should get a free main support girdle. When I get done with my PI head swap my next purchase is a Pro Mod short block & ATI P1SC Intercooler stuffing at least 12# of boost(hopefully 15# with proper tuning).
97 GT 5spd w/ too many damn mods to list. I can't list them all with only 500 characters.
170rwhp & 250rwtq before mods and 262rwhp & 305rwtq after mods with VT stage II cams & P51 intake coming soon with hopes of 300+rwhp