maybe... the casting numbers might help
if the motor is original and allways owned by you .a good chevrolet book might help like
chev by the numbers.
that bloc used more than one crank anyway.
whats needed is to measure how far down the piston travels from the top to the bottom
in inchs,that is measure the top of the piston at the bottom of the stroke.
also measure the valve combustion area with a straight edge ,that is from the lowest point in the chamber to the flat bottom edge of the
example 12 to i means that the piston
travals down the cly 12 inchs and is
copmpressed in an area of 1 incn.
hpoe this helps.................