I think that first sheet are theoretical calcs from the seller? (CNC Motorsports?) of the Stroker Kit. Notice is says, "Installation Instructions" on top.
Maybe those calcs are based on Buyer info or generic values. Jim Ward would know details.
The piston diameter on that first sheet is 4.080 (?hard to read, but calcs to 418").
But on the piston build sheet, it's 4.100
Also weird, the Kit sheet says IC745 Icon pistons, but the piston sheet says Racetec Pistons. ???