Trying to get the correct sfpm on a band saw

I'm rebuilding this old metal cutting band saw thats missing original motor has different pulleys. It has a reeve's drive and some gear reduction but I'm not sure it's realivant?

When I habe the dial on the machine set to its max speed of 450 sfpm
I calculated with a 6 foot 4 inch blade coming around about 19.5 times per minute, I have about 122sfpm. (The big band saw wheel is spinning about 38rpm and is about 12.25" diameter

The motor is a 1725 rpm. If I were to use a 3450rpm (double the speed). Motor I would asdime that would translate through out all the gear and pulley reduction and double my sfpm to 244? Still not the correct speed

Reeves drive pulley is about 3.5" diameter

Now there are 2 pulleys I can easily change, one is on the motor itself which is about 2" diameter
And the other pulley is outside of the saw after the reeves drive which is about 6" diameter (and looking at how close the belt is to rubbing the body of the saw this pulley is too big)

If I were to change this 6" pulley to a smaller one, is there a way to figure out what size I need to get closer to the correct 450sfpm with either the current 1725 or if I pick up a 3450rpm motor?

If you changed the 6" to a 3" you'd double the speed and with the 3450 motor you'd be right where yo ought to be.

Thank you that's what I figured, just wasn't sure if halfing the size of the pulley equals double the speed.