Sorry Denny, I don't deal too much in those little trucks. Just helping you come up with an answers. I know mine's an Eaton under my 63 K20. It was supposedly only produced between '62 and '72. When I went through mine it had stamped numbers under the rear cover and under the "hogs head" into the housing.
Is the track width the same on the AD series compared to the later ones?
Scott

Scott Ward

2 1948 1.5-ton Loadmasters
The red one and The snow pusher
1 1950 3100
1 1955.1 Chevy 6500
1 1954 Chevy 6500 2-Ton
1 1955 1st Series COE 5700
1 1963 K20 (454)
1 1964 C10 (350)
1 1951 1.5-ton Dump Truck
1953 and a 1956 Ford F800

Raising a teenager is like trying to nail Jello to a tree!