neu finned with 3905

[Wakesurfer]

With a big spur and pinion you may not have to take anything off fins. If you do have to grind a little it's not a big deal. Just tape up the holes in the ends of the can so you don't get any fillings inside. It's an aluminum can and fins, so it's not like the mags on the rotor are going to try to suck the shavings in. Mount the motor up with it clocked the way you want it, use an old screwdriver or scratch awl to mark the area where the fins hit the screw boss on the tranny. Little electric tape to cover the end bells on the can and then take the fins in that area down flush with the can. You might have to add a heatsink if you go with the smooth can. I just put a Novak HV 6.5 on another 3905. Not only did the fins have to come off the heatsink, but i had to cut a pretty big chunk of the heatsink shell off to to make it fit geared 12/68. The finned Neu was staying cool (120s for 5 minutes) until the MMM died, with no fan on the motor, just a hole in the windshield. It was close to meshing 20/68 with the fins, but I had to take a little off to get what I wanted.