8k rpm ...

I have a bit of time spent with a stock bottom end 340 at ~8k. Your needs depend on how much time you expect to spend up there and if you want it to get there in high gear as well as low gear.

The big end of stock rods will go egg shaped after about 125 runs. You can take them out and fix them once and then you throw them out. Stock rods are about all gone so...decent rods and light pistons. A good (roller) cam and valve springs, good heads and intake, probably a Dominator, and a well detailed oil system.