Engine rebuild choices

First off, if a motor is "above stock" it is high performance. A stock engine can be high performance. Look at the 340. High performance refers to things other than dyno output, too. Things like the forged crank you mentioned you have. That's a good piece, and it's high performance, because it has greater durability and endurance than a standard cast crank.

Iron rings, for example, are not high performance. You will benefit best from a moly ring. Anytime you talk about rings, it refers to what the top ring is coated with. So when you say moly rings, the top rings have a moly coating. Or chrome rings the top ring has a chrome coating. If you ever hear someone say "I have chrome moly rings" they are full of crap, because there's no such thing. They are either plain iron, moly coated or chrome. IMO moly rings will suit you best.

If you're going to buy any pistons at all, you may as well buy some that will raise compression. There are plenty out there to choose from. I would keep compression at 9.3:1 at the absolute most. This seems to be kinda a magic number for non quench engines, which yours will likely be. Plenty of compression to make gobs of torque, but not so much where detonation is an issue. Expect to run premium gas though, if you want anything that resembles a performance timing curve.