727rebuild/ front pump questions

Forget about what year the trans is or even what the numbers say. That means nothing. Compare rings. Don't mix pumps and drums without checking the rings. Don't switch planetaries from their original output shaft; sometimes they get burred and feel like they fit. Careful about the size of the locating dowel on the output shaft matching the back of the input. Direct drum bushing size changed; plus the corresponding journal on the pump. Check the direct drum for ring scoring. You can change a three plate direct to a four sometimes by using a forward bottom pressure plate on the top, but you might get a hard reverse engagement; have to use a C6 snap ring sometimes.