taylor there are many to choose from as stated in the earlier post, so we would need to know the intended application and use. h/p goals rpm and the state of the bottom end. what cc's do you want the combustion chambers, that will greatly affect compression ratio. are your piston's dished? what heads do you have now?
i am by no means an expert but i will try to help or guide you in the right direction. i myself run the tfs streets with the 72cc combustion chambers flat top piston c/r is now 12.5 to 1 i have to run 108 octane fuel at 7.00 a gal.
i was running the d3 head on the same bottom end and was using 92 octane with no probs. my heads flow out of the box 255 cfm on the ex at .600 and something like 340in. my home home ported d3's probably didnt flow 200ex.
ralph