Guessing that 65 used the 7260 small rear joint.
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Would be nice to know what his previous engine was? If it was a 6 cyl then the drive shafts were a smaller diameter.
360 in there, would be good to have a V8 drive shaft diameter to go with the extra hp of the 360. Just a thought, don't want him twisting a driveshaft if he is getting on it.