Help me build my SB Stroker

One nice deal about going with a 4" arm is the 340 or 360 deal really becomes moot. If you have a 360 block you can nail a 4.000 or 4.030 piston, then if you need a .040 piston, you grab a std bore 340 for a 4" arm. Need +.020 340, grab a 360 + .060, same thing.

Lots of combos in the SB with an arm, so pistons are really available in a size that will work.

I'd sleeve the one bad hole if it got too big, as it keeps more material on the walls and allows for potential future rebuilds.

Good luck with it.