Paul,
 I am confused. We were working IAW the attached sketch.
 Using a regular 540 thrust bearing instead of a plain bearing without
thrust edges, as illustrated on the sketch.
 Do you have misgivings with this arrangement? Milo

 Does this help?

 Paul Lamar

Help me here, I am sorry, are you saying that the 540 thrust bearings cannot
carry the thrust loads? Milo

I am saying it is not possible to use them. They are not in the right
places once you cut the Lyc crank shaft down let alone a pusher configuration.
Use needle bearings instead... for both pusher and tractor thrust bearings.

They are very cheap and lube is not an issue.
You will need them for the helical gear anyway as well.

The original Ross had all needle bearings for both shaft and all thrust
configurations. They worked fine for years and they weigh next to nothing.
You just have to be careful when using them in high RPM applications.
Those tiny needles get to go real zinging along :)
2700 RPM for the prop is no problem.

You can't use them on the prop shaft and still transfer the engine oil
pressure to the prop.

Paul Lamar