I have meassured the cylinder height from the top of the piston when it is in itīs lowest position in the hole(BDC) to the block surface and i got 3.858".
3.858"-0.070" deck = 3.788" Stroke?
I was basing my comp calculations on the standard 3.750"...

Am i doing it correctly?

Thank again for your invaluable help
(And I feel sorry for being so bore )