Originally Posted by Solara

I have not run silver can outdoor for awhile. But general rule about silver can for outdoor, final drive is around 4.00 and keep checking your motor temp (160 or less)...may be add extra FANS blowing toward the motor will work.

Go to here...

www.gearchart.com

There you will find the gearchart creator, click on there, and choose Schumacher Mi2 with 20T pulleys (same as Mi3)...once you are in there, punch in the 89 spur, and 40 pinion...then a table will list using a 40 pinion with 89 spur you will get a 4.01 final drive. So you should stock a 39, 40 and 41 pinion so you can move around the FDR. I would definitely try the 39 first and check the speed of the car and temp of the motor before heading to the 40 and 41 pinion.