To make the template cut a 1 3/8" hole with a holesaw on a 1/16" plexiglass.
Trim the edges to match the foot print of the engine mount. Mark the two mounting holes as accurately as possible and drill with a 1/4" drill bit and insert the mounting screws to test the fit on the engine.
This will be the pattern to modify the base of the Oberdorfer pump.
