With that comp ratio, Ive decided to do a little more work. I just got a Hughes SFI flexplate, ARP bolts, ARP harm balancer bolt and a few other goodies and sent needed parts to machine shop to be decked, balanced and line bored. In the long run, I hope to have a better big block, even if it is 11.5:1cr and running on strictly race gas. Hopefully it doesn't take them long, as I've never done any business w/ them. 11.5 to 1, 584/588 lift cam screams POWER to me. I hope it works. Paul, what gear ratio do you suggest, if not 3.89? Email is parpartgene@gmail.com. 406-939-1079 (MT)