Removed spinner, prop, hub, spinner back plate. Measured and drilled spinner w/ #40 at required spacing. Match drilled spinner back plate. Opened holes for #11 screws. Drilled and installed nutplates in backplate. Reinstalled all back on engine. .Spinner fits perfectly. Gap around prop blades is good. Filled engine sump with 8qts. Phillips XC 20W50 oil. Removed bottom plugs and hand pulled prop thru about 20 times. Motored engine for 15 sec cycles allowing cool down between cycles. Oil pressure came up on second cycle to 52 psi. Motored 2 more cycles. No leaks noted.