Vertical head gets pretty hot if you run for extended periods at 1400 rpm, I wouldn't want to run it any faster

and also worth considering removing the chuck, if on MT2 taper, whilst it's still warm, to save it jamming tight when it cools down.
Don't ask me how I know.

Too late by then. That will make no difference at all. Problem arose when a cold taper was inserted into a warm socket.

Almost exactly the same except I changed mine, from the (non-original) single phase fitted, to a 3 phase motor.

I’m not sure whether the vertical head rpm’s are the same as the horizontal output – I’ve simply never checked.🙂. I don’t thinkI’ve ever exceeded about 2000 (indicated rpm) on mine.

The power feed is operating perfectly adequately using the 3 phase motor and a 240V VFD.

I would not actually recommend a more powerful motor. The 2B was increased from 3/4HP to 1HP (over the 2A model). I am not aware if the gearbox internals were changed at all. If not, that is already a 33% increased rating. Mine can actually deliver about 1.2HP, but I am careful not to use all the power available. My Centec is a valuable asset and I don’t intend to try to destroy it by over-loading it!

There is a 7:8 ratio between, can't remember which way