Hey installing my new Prodrive...because the transom has a center support beam I am having to relocate the hydraulic fluid piston and reservoir. It says vertical mount only. Does it have to be perfectly straight up in down or can the bottom end lean back in a \ shape?

If your talking about the pump itself (motor / reservoir), then yes it can be mounted an a decent angle upright. As long as you have fluid filled above the pickup, it will pump. Its not suggested to put on an angle because it could suck in air and get air in the lines. Hell if it were completely full and no air in the reservoir, you could hold it upside down and it would pump.

Yup just got off the phone with pro-drive, you are correct