55312 Doug when you get the pump, see if it has a disc welded or riveted to the impellor. The water pumps used to come with 2 different impellors, A car with AC and Car without AC. You can CAREFULLY pull the back cover off and check for the disc. If there you have the high flow one. The other thing would be after cooking the motor, is to check and change the thermostat with new one. If not replaced, Check in hot water on stove and make sure it opens and closes all the way. I use a thermostat from Dodge BB motors. The opening on the thermostat is 30% larger than the FE one. You need to trim 2 mm around the outside edge to make it fit. It drops right in. An 1/8" hole drill to help get rid of the air in the coolant system. I was wondering if a 390 FE motor from a truck would have a different impellor with more blades and high flow?
Good Luck Rick L. I have an EDEL water pump on my motor now, no problems.
