So tonight found another hour.
Fitting longer threads for mounting midmount.
Threats exchance for the gearbox.
1:
Make longer threads.
Left the original one, on the right 2 new ones.
2:
Remove thread out of gearbox.
Welded an nut on the excisting threats.
Another pic
3:
Prepare new thread.
Twist 2 nuts against each other on the new thread.
Put on Loctite (blue).
Loctite 243