I suppose there could be some oddball issue with how the core was made up near the front.......but
Since the SBM uses a thrust plate to locate the cam...... I don’t know how you could have the cam positioned too far forward in the block.
But it’s probably worth looking that situation over.
Just slide the cam back in the block, put on the thrust plate and gear...... see how the lobes look when viewed thru the lifter bores.
