Looking for advice. I want to mount my four stroke engine upside down, but will have trouble getting the fuel tank centerline and carb to line up. Would a Perry Regulator Pump solve the problem?

Sure it would.

I thought the Perry would not work on a four stroke......maybe I'm wrong.. I thought the Cline was the only one that operated with a four stroke.
Please correct me if I'm wrong.

If you've got a Perry oscillating pump you've got to mount it somewhere on the engine... that goes for a two stroke as well as a four stroke. This type of pump is powered by engine vibrations.

The Perry regulating pump however works on the pressure fluctuations in a two stroke crankcase.
But it can also be made to work on a four stroke.
Every four stroke has a crankcase breather. It serves to expel oil from the case. If you connect this line to the Perry pump it will also work. The only think you have to make sure of is to put a "T" in the line so the excess oil still has a way out, and you have to keep the line from the case to the pump short and the one from the "T" to outside the plane longer. To make sure the pressure fluctuates enough.