Talking to Gary, you will get a HONEST Answer.
Soooooooooooo you could eather get a K&B Lower, and a CMB Power head, Or get the lawless lower and the CMB power head.
I put the lawless flex shaft in my K&B Lower, and havent had any breakage on the shaft.
Or you can run another powerhead.
I dont think you will be happy with a SS motor (stock).
If you want a stock SS motor, talk to me and i might be willing to part with it, 3-4 gals of 40 max through it, runs great.
NT