Not getting any replies? It has been awhile since I have worked with LBs but virtually any "F" series engine will work check that the crankshaft is drilled for self-propelled pulley. Even change the shrouds, gas tank, etc. if needed. they will interchange.

Walt Conner

What happened to the motor. Maybe it can be repaired.

Mowed 10 lawns a week for 10 years then 4 lawns a week since. I took the mower apart to sandblast and repaint deck,replace wheels and rebuild engine. When I looked at engine it had severe scrathes in block. Dont know for sure but it looks like it would take .20 or .30 oversize to make it right. Thought I would make it nice and pretty again and treat it a little better. Dose not owe me anything.

Sounds like a plan. There are plenty of F engine parts available. Good luck.