Makes sense and pretty much what I always thought, although I've never had a good look at a 312 up close. Dales post about using 309 impellers in a 312 made me wonder though. I assume he must be using ...
So is the 309 impeller and wear ring a direct fit in the 312 suction housing, or is there some sort of spacer or adapter required? How about bowls? Will a 312 bowl bolt to a 309 suction housing or vic ...