The following image shows the difference in planetary gear sets in the Ford transmissions:
Top Row (left to right):
Aluminum up to 1995
Factory steel 96 to mid 2000
Late 2000 on updated strength
Our gear Chrome Molly 4130 2 piece CNC
Second Row:
Aluminum 4 gear
99 to 2000 6 gear steel
2000 on update 6 gear updated strength
Third Row:
Aluminum up to 99
Steel plus 6 gear update