we just bought another 17a when you first start the machine it runs real rough for about 20 minutes and then levels out and sounds normal,ive drained the water from the diesel and changed the filter, it has a pressure gauge and it barely moves at an idle at full throttel barely gets in the green or what ever the center color is, it just doesnt make sense that it starts running right after workin it a for while anyone know what the pressure should be in psi? any ideas about the problem? Also changeing the bellow seals on one final,do they make a better type seal then the old style bellows?

Normal pressure should be about 15psi.
Check the by-pass valve/seat (on the side of the filter housing) for trash and proper seating.

Forgot your other questions
There is a duo-cone final drive seal upgrade.......Conversion Group # 8M3993.....don't know what the availability is but if it's like others it will most likely be made up of parts used on later tractors of the series.

I'd get the fuel pressure question worked out first and see if your rough running start improves.