Hi xtm, I am not sure but I think the 7.5 torson will not fit the Storm or Hyper 7, some of these Torsons have diffrent housing diamiters and I believe the Kyosho Torson has a smaller 24mm housing than other torsons. Remember Torson and Ball Diff are racing diffs and have a higher maintainance issue and have there own specificly recomended greases.
To use the Fioroni 7.5 Kyosho diff in the TK/BK kits takes a few mods to do but fits nice, here's some more comparison pics between the stock TK/BK ball diff and the Fioroni Torson.
