Magnum heads and cam selection??

The $800 ones are untouched and have smaller valves. The ones at IMM are like the Hughes "Super Prepped" heads ($1395). The Hughes Super Prepped ones don't include springs, the IMM ones in the link above do. You'll come out ahead with the IMM ones. I've dealt with both Hughes and IMM. Nothing against Hughes, but IMM comes out ahead in my book.