the 4.56 was the 3/4T, 3.90 gears will help a lot, my 58 w/ 283 and 3.90 rear will cruise at 65-70 comfortably [if noisy].... it's a 4x4? is the front axle ratio stock?

Bill


Moved over to the Passing Lane

"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir
"When we tug a single thing on an old truck, we find it falls off" ~ me
Some TF series details & TF heater pics