Cannot guarante that the hyper H345NP piston will have a 1.56" pin height.
The F-M book specs are 1.54" for the plane cast 345 piston and 1.56" for the hyper version. (I'm of the opinion this is a typo based on my past H345NP piston measurments.)
My old 350 had the hyper "H345np-60" pistons and had a 1.54" measured pin height. I measured myself when we tore the motor down for repair.
My block was decked a lot lot. Piston was .018" down the bore at TDC.