Dodge car hauler

Man that's really cool. Any idea on who it was originally built for or who all has used it?
Yes, the cab and chassis was bought new by Richie Sullivan in 1972. He was a race car builder, and he built the hauler body. It was used by him till the early 80s and then sold to Mike Williams who raced NHRA pro stock in the early 80s, and then Busch grand national and nascar north series.