Perry instruction sheet says "about 1-1/2 inches above the crankshaft centerline", so if you include the crankcase itself you've already got a little to work with.

My suggestion is to mount it as high as you can (opposite the carb side) and give it a shot. Remember that the pump is somewhat adjustable for flow. Also you don't want to use a super-stiff engine mount. The GF plastic mount used by klxmaster above is good, and a Hyde mount would give plenty of mechanical action for the oscillating pump.

Once you get it up and running, you will not regret putting the fuel tank on CG. Putting it in the nose will lead to constant fuel draw issues and elevator trim changes. On CG, the engine will run well with the airplane in any attitude.