Most all of my conversions have been done with a mandrel through the bearings. Been doing it this way since the 70s. Many of the swaps involved taking apart engines and gearboxes that did not need to come apart. Real PIA. But labor used to be cheap.
It was only a year ago that I realized I could use my milling machine to measure with. Wish I had a fancier way but my accuracy has improved a bunch.

The small multiplate clutches hold allot of power and the engine is real snappy. They work real nice in the cars I build.

Cheers, Charlie
If It ain't broke, Modify it!
87 Montero turbo Converted back in Spring1989
95 Montero SR 3.8 DOHC Only one?
93 Pajero 3 door 6G75 Mivec with paddle shifted 5 speed
Then a Gen2 SR with full coil independent suspension.