6 bolt crank is all you need but before you decide double check availability on flex plates. You'll want a high quality flex plate for that engine and sometimes 8 bolt ones are easier to find in the SFI grade. Head studs can be a nice upgrade but sometimes they'll interfere with the header flange. With the power you'll be making you need to upgrade a lot of the little parts. You'll need Cometic head gaskets for example, and the best bearings. The one piece rear main from Fast Fish is usually a good investment but you might want to talk to the engine builder before you buy too many parts. Some engine guys only want to use certain parts.