Converter problem?

The pump seal has nothing to do with directing oil thru the transmission. The fact it drops more is probably because I believe the gear ratio in reverse is not as low as first. The load on the convertor is slightly different as a result. but, I agree you should not have to idle the engine that high, nor should it drop that far. I would be looking at you initial timing setup and also the carb setup. It sounds like either the timing is retarded at idle or the carb is lean, or both. You should be able to idle it around 600rpm and it should drop about 50rpm regardless of gear.