I would heat the oil. It will stay warmer longer and heat from the very inside out. It was 30 something degrees in Dallas last weekend and I left the dry sump oil heater plugged in all morning. I would get the tank warm to the touch and spin the pump to circulate the oil through the system. Probably 5-6 times as things cool off quickly at maybe 40 degrees in the wind. You could do the same thing with a wet sump and a priming rod. Take the cap off, roll the engine around to the timing mark or #1 @ TDC firing, pull the distributor and the shaft and circulate away. 3 screws is no big deal...Run the engine, trans. and rear on the stands to get the water temp. where you want it.