Peter, I thought to go with 2 inch as well, which is why I thought of Kee Klamps as used in film and TV industry scaffolding. You could brace it forward and use a come along fore and aft to let the Beta "fly" at an angle.
You are welcome to contact me to come over and see the thing in action if you want, because even a look-see might save you some experimentation. Certainly, my "take away" was that the key is to spread the compressive load. I have a clue how Neolithic farmers might have pulled off Stonehenge now.
Yes, the chain fall is a thing of beauty. You could live with a half ton, as could I, but Fastenal sent me a one-tonne for the same price
, so I'm not complaining. The gearing is very low, which would annoy me on a job site lowering buckets of cement down to a foundation, say, but which is perfect for this application as it seems to take several "arm throws" to lower or raise the engine two or three inches.
Anyway, for reasons of safety
and investment protection, you CANNOT use whatever you without a dry run first, preferably on flat ground with plenty of space around. I hung from mine and twitched until I felt it would bear a non-twitching diesel
without stress, and yes, it was about as dignified as it sounds.
At least with a 38 HP, yours is about 120 kilos lighter than mine...a mere 170 kilos or so!