Regarding your comments about the timing.
In another thread on this board we had a lengthy discussion where yr brought up the issue of oil timing. Someone posted pictures of cranks and blocks. The cranks were all drilled the same. But the design of the sbm with its oiling to the mains being over to one side on the block,
Has the feed hole not on center like a Chev. If you look close at the main bearings the oil hole in the bearing is not in the center.
This slight difference in oil hole location is what yr claims shifts the oil timing slightly. After this was pointed out I inspected my block and looked at the direction of rotation versus the position
Of the crank and rod assembly and that is when I realized that when slotting the oil hole in the mains to 1/2 long, combined with the counterbore in the bearing saddle would allow the crank oil hole to get full flow and pressure at a slightly different position. It shifts the timing plus increases the amount of time that the rod bearing passage in the crank has to fill up.
Cole are you saying that you experimented with changing the location of the drilled holes in the cranckshaft?