Today, I ventured out into the snow and went to the local Lowes. I couldn't find the hex head countersunk m4 screws, but they did have some phillips head. So I got those.
After much work on the aluminum motor mount in the E Revo, things began to fit.
The 25 tooth Mod 1 pinion needed about 1/8" of metal removed to clear the teeth with the motor in position.
This motor is HUGE!

KB45 10XL 1200kv
Geared 25/40.
This is geared for speeds like:
4S = 36 mph
5S = 45 mph
6S = 55 mph
I have a feeling it will work well with anything from 4S to 6S, but we'll have to see about that.
Everything fit tight, but it did fit like a glove.
Check this out!