I found a way to extend it 1mm which makes me feel safer. I had to shim the bell out past the tip of the shaft 1mm. The bearing literally hangs over 1mm. I used a counter sunk washer that came with a shim kit a while back. I can let the bearing hang past the shaft yet the counter sink washer can still tighten against the end of shaft and I still have end play that's needed. Luckily, Ofna clutch bells is wide so the shoes don't hang out. I don't think 1mm on the bearing will hurt.
Attached a pic of the washer.
As to bigjayjay1 reply..the clutch has nothing to do with it. If you mount up a motor without the clutch assembly and see that the end of the engine shaft does not reach spur gear..shimming does nothing. There's no shaft left.
The mounts are simply not drilled/tapped in a neutral position.