Ross did my 451 pistons the same way. I asked for 11cc reverse dome (dish) pistons and they were fully dished?
I used the 4.15" crank in the new 500" 400 block because it uses the longer rods and pretty much drops in with no bore notches needed, just a bit off the oil pickup boss. The piston pin just goes through the lower oil ring land (1.122 compression height.) I also originally planned to spin the engine pretty hard (7,000+ RPM), and I liked the 12.4:1 compression ratio with the flat top pistons and 75cc Victor heads.
The 4.25" stroke, 6.535" rod stroker kit (I'm too cheap to go with custom pistons) is heaver and the piston forces (speed and acceleration) are higher.
One issue for me was to take some stress off the stock block.
I do like the 4.25" stroker kit for hot street type builds that only spin about 6,500 RPM max.
With 84cc RPM type heads, The Flat top pistons end up around 11.7:1 compression which is likely too high for most "street" pump gas combinations, and sort of low for a bracket engine build, but the 75cc Victors would make about 12.8:1 which would work good in a bracket car.
The 440 source / ICON pistons "Dish" piston is 24cc. This drops compression down to 9.88:1 with 84cc heads which would make almost any combination able to run on pump gas.