Another way to get a safe mount is to bolt a piece of 1/2" X 2" flat bar about 16" long to the block using the top bellhousing mounting holes, and spacing the lower engine stand arms out 1/2" with a stack of flat washers. It allows some better positioning of the arms to achieve a more neutral balance point when the engine is rotated for access to the crankshaft and connecting rods. Those things get really top-heavy, especially with the cylinder head installed!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!