I owned a '65 Chevrolet L80 Holmes Wrecker, for a few years. Sold it 2 years ago. It was equipped with a 409 eng., 5 spd. tranny, & 23000lb. Eaton 2 spd. rear axle. Had full air brakes, & power steering. I also had a 1960 Chevy L80 tractor, with 348 eng., 5 spd. tranny, & 2 spd. rear, with full air brakes, & power steering. See them here,
http://classiccoe.com/oldcoetrucks/6066.htm