There should be cg in "the manuals" some place. I mostly use my head. Put it up a foot, and bounce it a little See what it "feels" like. My neighbor was GIVEN a Mohawk, which makes my Challenger look like a toy. One advantage to his, is that the arms lock into place. This could be a help if something 'tried to move' For example, if you got the "short arms" to far "in" with, say, the engine end over them, and it tried to tip forward, I could see it would try and pivot them to the rear, further amplifying the problem.
One problem I have with the Dodge and 1/2T Sierra both, is that when you extend the short front arms in, you have to really fiddle sometimes to get them to 'set' on the frame, as the frame of course curves upwards to the suspension This of course is particular to this hoist, one with different dimensions might not be a concern. Mine is only a 7K hoist, and it is getting on the short end lifting the Cummins. Keep that in mind when you buy. My Cummins is not a 4wd, so it is a bit lighter than 4wd models.
