Those mentioned do good work on Raptors but dont leave us out of the mix. Our Raptor 660s are no slouch! Depends on how deep you wanna go into your wallet but a 686 w/LOTS of porting, 39 FCRs, Big Cam, Big Piston, and Dual pipes will be more than a handfull. Way more if you go stroker or big bore. Give a hollar sometime if i can help.