Future build option brainstorming: current combo is a .040 over 400 - 451. Turned factory crank, 6.76 rods & Icon 1.322 ht pistons. CNC’d stealth heads.

Looking at the future with my 400 block, and a 512 kit would be my preference, but my block has been decked slightly and mainline honed, so I believe the deck ht to be 9.960. The 440 source kit puts the piston right at 9.98. So what are the issues with running .020 above deck? Obviously head gasket choice becomes paramount, clear of the bore and thick enough to keep the pistons off the head. What issues are there beside that?

2nd option is the 500 kit, this combo would keep the piston within the hole, but I want longevity, and I’m not crazy about the short piston ht and oil ring support rails in this combo. Weigh in on those issues if you have input.

Lastly, I could get a set of 6.700 BBC rods, use my existing slugs and turn my crank to 3.875 and land at zero deck for approx. 470 cubes. This would perhaps save me a little money that I could put elsewhere, but probably not much. Also, both of the source kits are available @ .042 over, so I could hone to those pistons from where I’m at now. Current bore is in good shape, but I can’t help but think if you’re going to rebuild, you might as well have new slugs and such.

Goal is approx. 650 hp, or whatever I need to put my B-body into the low-mid 10’s. Thanks for your thoughts.