first off thanks for a great website and all the good advice.I have a 1948 3/4 ton chevy truck with stock 4 speed and a 4.57 rear end. the engine is a 1967 250 cu in 155hp chevy inline 6 that runs great. the truck has 16 inch wheels with radials. the truck seems happiest at 45 to 50 mph but will run at 55 to 65mph. no tach on the truck. Is it bad on the tranny or rear end to go that speed?I don't want to change the rear end since I use it for hauling
