switching from 904 to a A500 or A518, anyone done this?

switching from 904 to a A500 or A518, anyone done this?

A good friend of mine has a 518 I'm gonna go look.At tonight, and I have a huge cooler and larger lines on the 904 now, I really need the OD it will taim the 410s down and I'll talk to the guys that built my 904 about drilling the shaft, thanks for the info and the links &#55357;&#56842;