Here's the way I see it...
C6536S225898
C = Conventional Cab
653 = Model 6503 (with the third number dropped), 175" wb
6 = 1966
S = St Louis Plant
225898 = unit number starting with 1000001 (so you have the 1225,898th unit out of "S" plant)
Engine could be the 292 Six (170 hp) or 366 V8 (220 hp).
Transmission could be any one of 2-different 4-speeds, 5 different 5-speeds or the Allison Automatic.
Rear could be the 15,000 or 17,000 pound Chevrolet Rear in either single or 2-speed.
Mike B
