327 and 350 engines both have a 4" bore. The 350 has a 3.48" stroke vs the 3.25" stroke of the 327. All 350s have 2.45" mains, but 327s had 2.3" mains until 1968 when the mains were enlarged to the same size as the 350. So, if you've got a '68 or newer 327 block, the crank will fit. If earlier, it won't.

Bob