Pulling a 5th wheel RV trailer with a 1/2 ton.

It is in a Big-10 or GMC Heavy Half..
I ordered that truck new. The only new vehicle I ever sat down and spec'd out everything and ....waited.

Bought in 1978 and Sold it in 1992 with 205,000 miles and the rear only had fluid changes.

I did get a trans rebuild at about 120k, Build by a local company called "Level 10" with a 'towing convertor'
After 15 salt road winters the rust got to it. The pictures above are from 87 and 88