I have a 1995 Club Car Electric,http://picasaweb.google.com/rodnhower/Golfcart#
It's a stock 48 Volt except for an Alltrax 72V, 450A control and 8, 6 volt SAFT NiCad batteries.
I design motor controls for Kinetek Controls and plan on installing an AC induction motor and 450A control.
The motor has no problem going up to 7000 RPM's.
I've seen gear ratio's anywhere from 12:1 to 10:1 and the high speed after market sets that are 8:1
I don't need 8:1 since the AC motor can safely run at higher RPM's than a brush motor.
I actually have a choice of 10:1 or 12:1 since AMD (advanced motors and drives) makes a Kinetek transaxle with these ratios (they also do a 16:1) that will mate to my AC motor.
AC motor picture and control,http://picasaweb.google.com/rodnhower/Kinetek#
I used the same AC induction motor on a Fairplay Goat that has 16.5:1 and 22.5" tires. This thing easily did 25 MPH (speed limited, I actually ran it at 30 MPH with a software change). It had lots of torque and would climb anything but a tree.
So, I know the motor and control will kick butt on my CC.
Here's a picture of the Goat,http://picasaweb.google.com/rodnhower/Goat#
You can also email me directly at rodhower at ameritech dot net