I did look over the the Rc10. It looks as if the motor will physically fit. I would have to find a spur gear.
This motor does look like it would be huge. I have been driving the revo so long I forgot how small this other rc is. I'm also noticing how small the drive shafts and connecting knuckles are looking on this thing.
I'm going to think about it more, seems like a better idea might be to sell the 1512, and find a good deal on a motor/esc combo.