Since I've been in the OS mode the last few days, I dug out my LA .46 which has mostly ran as a Diesel conversion. Very user friendly engine.
OS=== =LA .46
Prop===Zoar 11x6 as per recommendation by OS
Plug===Fox #8
Fuel===WildCat 2/4 with 18% full synthetic
Max rpm with stock muffler==11,222
Max rpm with Bisson Pitts===11,467
Idle 2,200