If I was to buy an imco 2" shorty case would everything out of my STD Bravo case fit inside the imco minus the vertical shaft?

Yes. You might have to add the cavitation plate IMCO makes to your upper. Comes with the -2 lower kit also along with the -2 shaft, 2 bearings and o-rings.

and if it has a lwp you will need to monitor the water pressure..

Not to sound stupid but what is lwp? Low water pickup?

Yes, Low Water Pickup

Does the Imco low water pick up push more water pressure than the Merc. DWP case?

Yes.

Chris

I am pretty sure that the IMCO lower uses a different bearing carrier for the propshaft.

To answer your question, yes all the guts will fit, minus the vertical shaft.

The standard Merc bearing carrier will work.