I bought a '56 Plymouth engine in Fresno, a 90 mile round trip. WIth the 3:73 differential, that 800# engine did not slow down the old truck one iota on the return ride home it ran very smooth at 65 mph. Stopped for a taco at a roadside 'kitchen'. One of the best taco's I've eaten. The owner/cook liked the truck. Found out he was born in 1952 so same age as the truck, neat. Another one of the priceless intangibles of driving an old vehicle.