albatross said:
most 3.76' stroke cranks were used in 366-396-402-427 displacement bbc engines, and as such the cranks had counter weights matching those piston and rod weights, cranks generally have counter weights designed for a certain range of connecting rod and piston combo, your use with a larger heavier piston may require a good deal more MALLORY METAL (heavy balance weights) inserted in drilled holes in existing counter weights and that can get rather expensive when you balance the rotating assembly, you generally cant weld excess metal to the outside edge of the counter weight to get the wight required due to the need to clear the piston skirt needing to clear the counter weight passing under the piston skirt at bottom dead center on the stroke, (thats one of the reasons why 6.385" and longer connecting rods are generally selected on many longer stroker cranks, IE the need to clear both the longer stroke and larger counter weights required) and your block will need to be sonic tested , bored and honed with deck plates, a good machine shop should be where you start as they can measure and advise you on what to buy and the cost of the machine work and parts
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you might want too read carefully thru these threads posted above and their sub links and play with this calculator I will link too below
https://www.uempistons.com/index.php?ma ... aaaf4455f4
youll quickly see that an increase in bore diameter alone tends to increase displacement, which if no other changes are made also tends to increase effective compression
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