Because of the oddball bell housing bolt pattern on the stovebolt six, I add a piece of 3/8" or 1/2" steel plate about 3 X 12 inches to the back of the block to extend the lower mounting arms a little, and add a few flat washers ahead of the upper mounting legs to make the engine sit level. I've also added a front caster wheel that extends about a foot ahead of the harmonic balancer to prevent the stand from tipping forward.
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!