That hauler is John Dieanna (SP?) old 1974 hauler that Stevie had the front frame behind the cab cut off and had a F7000 or maybe a F8000 Ford complete front end with a CAT V8 diesel welded in and adapted for him to use the more powerful with better fuel mileage CAT diesel motor and tranny to haul with several years ago. I think that truck had either a 360 or 413 gas truck motor in it originally that got around 4 to 5 MPG best ever.
That 1970 Plymouth was his 440 6 pack car that he raced for some time before building the 1962 Plymouth M.W car he is, I think, still racing now.