I built a 383 a couple years ago, Put it in My 54 GMC Panel and really like it I used a good set of 71 350 heads (75cc) that I had to save some $. It is now time to change them. I have to run 93-94 octane to keep it for detonating. Am I going to have problems going to Vortec Heads with the smaller cambers or is the chamber design enuff better that the comp increase won,t detonate Thanks in Advance