8/9/10 speed cassette hub on 7 speed xt m732 rear hub.
Heres a few pics. In no particular order!
1st is a problem you might hit, the raised section is often thinner on an 8 speed freehub, the cassette bolts then foul the hub.
2nd the spacer that solves the above.
3rd compaired hubs
4th finished hubs.
5th using a mix of the old cones and seals, respaced and swapped spacers....just keep putting the cassette on and trying it in the frame if your not sure of your measurements. The closer to the frame the less dish, the less spoke tension % difference, the stronger the wheel.
Hope they help.