Hi,
I ordered the seal and o-ring from NAPA, and neither are correct. The parts are the correct numbers and images as provided on there website, and from what the counter guy pulled up. BUT the O-ring is not even a o-ring, it looks more like the old seal, but is way too large. The seal is the type with a spring, but too large too.
The part numbers from NAPA are:
Seal ATP 1-5043
O-Ring ATP 1-7453
So I read the treads about using one from 73 chevy truck with 400 trans, looked the part number up for it on NAPA and it is the same part as above(ATP 1-5043). The OD is too large by about .12 and the ID is too large by .03
The outside rubber is so hard on the seal I can't get it to squeeze down to fit inside the gear at all. This seal looks more like a valve stem guide seal.
I will work with my NAPA friend to see if there is a "correct" number to order.