360 blocks

Are the earlier/older 360 blocks better than the newer ones? I've heard that some of the 1st 360s were built using 340 cores thus resulting in thicker cylinder walls. Have and engine now that I'm certain has cracked on the backside of cylinder #8 and think the block is a early 80s but have to double check. Engine has 12:1 compression so maybe looking for another block. I know any block can be junk, but was going to try and source the "better" year blocks if there is such a thing.