I asked Mary Schorr about the pic. He was instrumental in the success of motion. Here is what he told me.
I took the wheelstanding photo on Sunrise Highway (not really a highway!) outside of Motion. I'm guessing it was taken in late 1968 and I'm not sure if Joel was driving or Billy Mitchell who was the car's regular "shoe."
I shot it on a Saturday with my Nikon SLR filled with Tri-X b&w film rated at asa 400. I believe the lens was an 85mm Nikkor.
Joel had just dynoed it for running on Sunday at New York National and they were checking it out. The big-block Camaro was the black 1968 model that was run during 1968 and 1969 seasons and set a long list of NHRA records. After the wheelstand he made a full pass, came around and did it again. Yes, there were no license plates on the car!
There are some other shots of it in MOTION Performance, Tales Of A Muscle Car Builder.