What's the timing set at? The Hi-Volume oil pump is a no-no with a stock pan, pumps too much oil and will pump the pan dry before the oil can drain back into the pan! Plasti-gauge is just not a good way to check bearing clearance IMO..... Did you check the crank journals with a micrometer at all, were the rods re-sized? (stock rods have a habit of going egg shaped, no way to get proper clearances with an egg shaped big end on the rod) Did you "burp" the cooling system? An airlock in the system will cause severe overheating!