Ok the main thing for power is to have a straight bore, so ring gaps stay constant. I have three standard 340 blocks that look fine with no ridge. I hope I'm luck enough to be able to leave one standard with a hone job and run it!
You probably can. Forged pistons require a bit more clearance anyway. I have run .010" piston to wall clearance before because that's what I HAD. The bores were straight, but big. One of the strongest running stock bore and stroke street motors I ever had and it didn't smoke and had good compression, because I file fit the rings. It did have some piston slap when cold. Sounded like a diesel but all that dropped out when it warmed up.
My motto is as long as they ain't got enough clearance to swap holes, run um. LOL