never say never when discussing 50 year old trucks, back then absolutely anything made could have been ordered .... the difference in the 4000 and 5000 series GVW ratings is in the front and rear suspension and wheels and tires, and not much real difference from 55.2-59 ... you really should confirm what the truck actually has before planning on major changes for minor advantage

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 & Rust-a-holics Unanimous parking lot