I am very new to cnc and I have a question of sorts.

I happen to have a Dayton 2m191 1hp 10,000rpm AC/DC motor. The motor is shorter than the 1/4 hp that came with the mill (7.5in) and very close to the same diameter. 3.7+ on the 1/4 and 3.8+ on the Dayston. I was wondering if switching out the motors would have an advantage. I would have to make a new mounting plate or remachine the mounting holes for the Dayton in the original plate. SInce their physical sizes are so close I dont think the weight would be a factor. The Dayton is rated at 12amps full load and I have the variable switch used for routers which is rated at 15amps. This would allow me to vary the rpms without changing the belt. My current set up has a 1/2 wide flat belt running on the middle flat surfaces between the 3rd and 4th pullyes. I would also have to mount some thing to measure rpms.

Would having 1hp really be that benifical? Whats the best way to digitally meassure the rpms? Is there a better way to do what I am thinking about?
Thank you
MIke