I have a 87' with Alpha drives, when setting ether in the trailer position or down my port drive slowly drops ( an inch or two a day ) can anyone help me with this? could I be low on oil?

not low on oil . You either have a bad seal in one of the rams or a problem in the pump itself. In the service manuel there is a series of test to locate the problem.

The pumps have check valves . Inspect the rams for leaks if none are found ... Pull the pump apart ... clean the valves and reinstall.

Bob

no leaks on the rams, I will look at the manual again didnt see any type of troubleshooting first time through, no sign of leaks on the pump ether I have the oildyne/eaton pump

I had the same problem before. It was in the trim pump. I got a good deal and just replaced the entire pump assembly.

depending on the year trim pumps are either internally bypassed or have a manual release. look for a sloted screw head between the trim lines and check for tightness. other wise the suggestions abvove pretty much sum it up.