THINGS I KNOW:
First guys, I appreciate all of the input in trying to sort this out. I think Dick has a great insight on what's happening inside the drive. You must have an air space. It's not going to starve the drive it's going to allow for room for the oil to expand inside the drive and room for the oil to move. This is due to the straight cut gears. All drives can benefit from adequate air space even Bravo's could really use more. I use the Torco RTF fluid as recommended. I do turn mine up to 6200 rpm which could attribute to my symptoms. But one thing for sure, you do not want to continue to fill the drive past the vent hole while filling from the bottom. It's probably to late for most of us to offer much more input until Spring but at least we all have the necessary information to watch our drives for potential problems.
Participation and discussion is what keeps this forum interesting. Any other thoughts along the way would be appreciated.

I turn my motor 64-6600 RPMs

Glad to see you're one of my kind.

I fill mine to the top vent plug then added to my non imco reservoirs. Use the Torco RTF. No oil in the bellows. I ran hard this fall. Noted drop in level, but after the initial drop no more. Since air volume expands more than fluid, the more air in the drive the more movement of fluid to the reservoir you will have. Personally I don't know what difference any of this makes other than it may be an excuse for imco as to why their pinion seal has leaked.....

Drives filled incorrectly will probably run inefficiently and rob speed. The oil has to move into the air space or you will hydraulic the gearcase and cause unwanted pressure. Just my thoughts.

I will admit I know nothing about these drives but...

It would make sense to me that a pinion seal would be much stronger then a check valve or reservoir cap, so if the fluid was going to push out anywhere it would follow the least path of resistance. If the pinion seal is the fluids first choice then thats one really strong check valve and reservoir cap!

I agree, definitely need an air space..

And then there is the one issue of orings on the pinion bearing unit.. My friend replaced the orings with thicker ones and no more oil in the bellows.. Something to look at.
I will only be turning my motor to 5600-5800.. liquid rollers..

Where is summer when you need it??

Is anyone but me surprised that IMCO has not posted anything on this thread? I would think that a lot of their business for the SCX comes from people that are a part of this website, whether a lurker or an active poster. Seems to me that in a way, you are doing a fair amount of R&D for these guys, the least they could do is add some guidance. I think that these are the drives I will use on my boat, but stuff like this makes me question them.

x2

i'll keep you posted on how IMCO handles my leak issue and shifting issue. All i know is I bought two drives, one doesn't leak and shifts great. The other leaks through the casting and shifts like you need a leverage bar. Which is fun when your trying to dock and need the starboard drive. They stated shift cables are the problem, so I switched the drives around. Now i need the leverage bar on the port side.