Since they all turn at the same speed, the pumping capacity is determined by the diameter and height of the gears.
The M-45 gears ar 1.00" tall by 1.50" OD, with seven teeth on each. It's the largest pump that fits directly that I know of, and is quite sufficient for a 261.
Cool. Thanks, panic (and Hotrod Lincoln)! At this point I'm going w the M-45 and just trying to find a suitable pickup for it.
I assume someone previously fixed the 261 I'm building with whatever they had access to, hence the '53-54 corvette 235 pump.
BTW, I added a comparison pic to my previous post.
