Man, what I wouldn't give for a RM 250 / 400 roller, I've engineered the shit out of a PE 400 frame so far to get it where I want it but at the end of the day a RM frame would have sufficed nicely - that said, a PE 250 or 400 motor will sit in a RM frame with the exception of the front mount being different on the 400's (15 minutes work to make new mounts) At the risk of trying to re invent the wheel, I am currently going hard modifying a PE 400 motor and frame to a place they were never designed to be! Shit someone has to do it!!