Recently I had a 383 engine built including boring to 060 over, roller cam (good torque) roller rockers, clevite77 bearings, hyperutectic pistons, etc... The problem I am having is an oil leak that is somewhere up in the bell housing area as the oil drips down mostly on the drivers side by the dust sheild and dripping onto the header. The oil is not coming from the rear main seal as the crank flange is totally dry. The leak gets much worse if I work the engine hard, Ie: Highway driving above 65, long steep grades, or when I am pulling the boat at speeds over 60 or up hills. The temp guage has never indicated above 200F and reads at 190-195 unless coasting down long grades. When engine is working hard oil pressure drops progressively from about 65psi to 45psi at about 2600rpm. I havn't been real impressed with the power output with this mill especially passing power as I thought I had built this engine to really be in it's power band above 2500rpm. I have chalked most of the lack of performance up to running 3.73s with 35" tires. The compression is 9.1 to 1 and does not ping on regular gas, however on occasion when I restart it does crank a little slow from timing being a little too advanced.