1. my slide comes all the way out over the motor so unless i mount the motor backwards ill never have the room.
I know. I think it is worth considering.
2. the original mount is way to small for the new bearings.
Was suggesting to use the concept. Not the same mount.
I disagree as long as you have good bulk on ether side of the bearing your just not going to apply enough pressure to the bearing collar to get it to deflect, the inside has 200mm of cast iron slide and the outside had 30mm of Ali, im exposing probably less that 1/3 of the bearing which is hardened steel, the motors will give out or the belts will break before there is any significant deflection.
comments anyone with more experience?
It all comes down to the final rigidity of the machine. Motors and belts don't give you rigidity. Frame construction, mounts, bearings, slides and screws do. Your setup may and probably will work fine, but will be far less rigid than a proper steel mounting blocks. Depends on what you intend to be using the lathe for I guess.