I did my conversion for Z32... tranny, clutch, some mods to firewall to attach clutch paddle, paddle set (manual), clutch oil resevoir, rear diff (manual/auto different ratio). Mechanic says Nissan ECU auto can use for manual, but not the other way around...
... maybe he was wrong because I had to change my ECU also... engine not smooth after conversion, but after ECU change, all is well.
good luck
m