any model could be a "farm truck", the 3100 is a 1/2T, the 3600 is a 3/4T .... the chassis difference is primarily in springs, wheels, and rear axle, not the "frame" itself, which are just different lengths .... all conventional cabs of a year are identical, and the front clips are the same 1/2T to 1T

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