Ive got a d16z6 with 67k miles runs like new high comp. #'s, with header/intake/FPR/zex cam/cam gear, if i retard the ignition 4 degrees and run azex plugs would i be safe running the 75 shot at the track? or should i stay with the 65 or 55.

 

I've run bigger than that with a stock engine before, you'll be fine as long as you don't run out of fuel.