I think these guys are on the right track.

Just a side note, never put a vehicle up on concrete blocks, cinder blocks. They're not designed to hold weight concentrated in a single spot. A lot of people get hurt/killed that way. When I was real young I did that, not knowing any better. I didn't have any problem but after I lowered the car and was carrying the concrete blocks away one slipped out of my hand and broke into several pieces. I bet it fell no more than 3" off the ground. Opened up my eyes. Use jackstands instead ....from Harbor Freight or somewhere else.