I don't know if this will help, but. I used one of those stands (looks similar). I had to use the top 2 arms as a spacers and the bolts screwed into the block on the top 2 holes left and right of the center bolt hole. The lower arms were used as you have them in your picture, bolted into the lower bolt holes in the block. Bolt it on while engine is on the floor and then lift the engine up and slide the tub onto the stand.

51 GMC 100 with 59 chevy 261 under the hood.
3 on the floor with 3.42 gear.