I designed a mount to utilize 3/16 plate and a TH400 mount to help support the unit. The cross member is one I have for my 56 Chevy that I never used. It'll need to be modified to fit the truck frame and mount I designed. I just want a helper mount that still allows the stuff to twist. Of course this would mean five points of engine/transmission mounting, so it should be good and stout. I haven't installed this setup yet. Right now I'm searching for threads from people that have installed the Ranger and what they encountered. I don't fell comfortable hanging 215 pounds of cast iron off the bellhousing.
I've seen somewhere where the guy made a mount to utilize the rear cover bolts on the SM420. It was a slick mount, but I had already had my pieces plasma cut by the time I saw his mount design.