Hi George
Those are decent sized brushes - but it looks like only four of them
The motors we normally use have eight brushes - 500 amps should be OK but probably no more than that
I suspect you will be getting more torque per amp than I do with my Hitachi motor
It's 67 volts and 1400 rpm
With a 144v controller you may run into the problem that I did when I went to 130v - goes really well but runs out of puff at the higher revs
You may have to jack the voltage up to get highway speeds
The yoke is great - should be able to tap out the spider and fit it to your propshaft - you will need a propshaft with a sliding joint as well as the UJ's
https://www.diyelectriccar.com/foru...-dubious-device-44370p9.html?highlight=duncan