Casting Numbers

Yup, that casting number is not the same as the part number. If it's a genuine '68 box, they made two different housings that year....an early '68, and a late '68. IIRC, the difference was in the diameter of the input bearing housing. The main housing was the same one for all the engine sizes and both A and B bodies. It was just early or late '68 production dates, and I'm not sure when they changed over. I've swapped complete boxes from just about all years from '62-72, ones that have the small sector shaft. It's mainly the control valves and/or fittings that are different between models, engines, pumps, hoses, etc. There are some appearance differences however over the years.