[CaptPat]

Now I see why I was having difficulty identifying a replacement engine.

 

[CaptPat]

Yep, Pat.

As others have mentioned here a good small engine shop should be able to help with a new motor of same type, and a crank swap, as they are still available.

It will be costly, but if you really like that machine, perhaps worth the effort.

Toro Brand loyalty should have you in their best interest, but they rather sell you another new model.

Not gonna spend a lot of money to get it running, it's my son's the engine is bad and he was going to sell it for parts. I thought that repowering (if cost-effective) would be an interesting winter project and it would replace my aging Troy Bilt mower. I was hoping that there was a nearly turnkey solution, but that was before I found out about the special shaft. So I am not taking it to a shop, or getting a bunch of machine work done as the money spent there will probably get me pretty close to a new mower. Plus there's a limit to how much tinkering I want to do, redoing the drive system to accommodate an engine with a different shaft, as well as hoping the BBC system still works is beyond what I'm willing to do.

I do thank the folks who've posted here as that has been helpful.