454 cu cooling problem

[EdV]

Posts: 1


454cu Cooling Problems
HELP! I have a 1983 454cu motor installed in a 1970 ¾ ton GMC Pickup truck. Confounding problems with the cooling or should I say overheating problems but not really boil over as long as I don't let it idle too long. . The motor will remain at normal operating range as long as the vehicle is moving down the street and without the AC on. Lost at the dilemma I had the motor rebuilt, but it still ran really hot. The shop tried different water pumps for the 454 funny thing all of the pumps were too long to fit with out hitting the radiator that must be because the truck came with a L47 400cu motor according to the specification sheet that came with the vehicle. I replaced the water pump previously, we compared it to in-stock pumps at the auto parts store the only match was to the 400 motor. Checked or replaced all of the components that the pros have told me, such as various radiator caps, thermosats 160F,180F, 195F. cooling Fans; electric fans, flex fan, clutch fan,I now have a6 blade direct drive if you will. new rebuilt 4 core Radiator, vacuum leaks, timing, carburetion. I was talking to a guy that said he had the same problem his remedy was something about the crossover in the intake manifold ? and that the timing gear alignment could be adjusted? Now this was quite some time ago I am pretty sure that is what he said. What are your thoughts, anybody that can help out with this situation will be appreciated. EdV