Yes usually the 8.75 was not in 3/4 and 1T, the 9.25 replaced the 8.75 in the 1/2.
1T had 60's for a long time before 70's got under there, D-70's didn't get into and Dodge till 79, and weren't in the normal 1T, there was an option for the 60HD and 70 in the W-350, but most were regular D-60's and the 70's were used in the larger trucks.
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