Right on... with hypers and SCAT rods I would expect it to balance out internally by removing material from the cast 360 crank. Perhaps to include boring out a bit on the inside of the journals. I have been meaning to try to figure this out.....
My 72 cast 340 crank is internally balanced. I have the pan off, I'll need to look. I have Scat I-beam rods and heavy TRW forged pitsons fly cut to zero deck. The cast 340 has a different balance than the 360 and as I recall is was on the lighter side like 12 oz? My fly wheel for the cast crank had 3 ~3/8" drill points.