Mercruiser Alpha motor support sleeves...?

I recently met a guy who saw me "blocking" my stern drive motor with a block of wood and showed me a better way. He had two "sleeves" that were made out of some type of plastic. They looked like he had sawed a 1 1/2 inch pvc pipe in half lengthwise (about 10 inches long) but he said he'd purchased them at a marine supply store somewhere. Does anyone know where I could find a pair of these? They were nifty in that they snapped on the chrome part of the lift pistons so you could do this task yourself - instead of needing two people. Thanks for any responses.