Lorn asks:

> I don't know where your engine came from but I would guess that you
> got it from a twin Comanche.

Actually it is a Lycoming O-320-A2B, originally installed in a
Piper PA-25-150.  Until just now, I didn't know that a PA-25 is a
Pawnee. The engine is for fixed pitch prop and straight conical mounting.

> The only fuel balancing that I have ever heard of on a 4 cylinder
> carbureted Lycoming is a spacer between the engine and the
> carburetor on the twin Comanche.

Interesting. I don't know much about Twin Comanches, except
what the second engine is used for. I did look around the web
just a bit and found a few references to IO-320 and turbocharged
variations, and dynafocal mounts. I would like to see a picture
of the Twin Comanche induction system showing which sump is used
and the carb spacer.