Danged if this site doesn't get me second guessing myself on everything. I went out & checked my trans. Looks to be a 64 to 70 gear set with ratios of 2.66, 1.91, 1.39 & 1 to 1.
Case is aluminum with these numbers cast into it
04A1982
C-13546
Tailshaft housing looks like iron with this cast into it
C-96706K
Stamped pad has what looks like PP833 6 4 82
So I'm thinking 1982 case with earlier gearset. Sound right?