You need a forged crank for the modular motors to do better than 420-450 hp safely. Iron block is heavy, but you can get a cheap, strong, and light aluminum block out of a lincoln or mustang depending on if you want a teksid or WAP block.
Ported stock heads still do well. The trick flow heads are great if you want to spin tons of RPM, but for a budget there is nothing wrong with ported stock castings. They will easily reach well over 500 hp.
Ported stock heads still do well. The trick flow heads are great if you want to spin tons of RPM, but for a budget there is nothing wrong with ported stock castings. They will easily reach well over 500 hp.