I'd suggest getting a welding shop to cut out a donut-shaped piece of 1/2" steel plate about 18" in diameter, with about a 6" hole in the center for crankshaft and rear main bearing cap clearance. Drill one set of holes spaced for the back of the block bolts, and another set for the transmission-mounting holes at the back of the bellhousing. Out near the edge of the plate, drill some holes to attach the arms from the engine stand, spaced so the engine will balance well when rotating the head of the stand. The same adapter plate can be used with the bellhousing on or off. Just be careful with the bellhousing attached, as it makes the engine assembly front-heavy.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
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