RJR, Those numbers have been thrown around plenty on post. They are the parts #. Sorry I left off the zero's
I have yet to meet a MTH PS-2 5V engine that would not take a PS-2 3V board in the engine.
I just point out there are alternatives if you can' fit it in an engine.
At this point, having tried to put a PS-32 in a FF Electric and just completed one in a RTR 4-6-0 starter tender, there will be fit issues because the board is taller, doesn't mount upside down (yet) and therefor position is more critical.
Big engine, tall shells, won't be an issue. Others just might take more planning. Good news is no battery or charge port. G
The 4-6-0 tender had the speaker in the front. SO the board had to be mounted in the back. The tender slopes down at the back, and the mounting bracket raised it too high. So I had to exclude the mount and go direct to the chassis. Basically had a smaller foot print on where I could put the board.