I got hooked on the looks of them in the late 50's, A quarry near San Antonio had 4 of them and a guy I went to school with drove one of them. I did the next best thing and bought a 550 with a 370 V8 with 232 HP that would outrun any 671. I was considering buying an 860 somewhere around PA in 2009 when I bought a 1957 600 wrecker in Walnuts Port, PA. My wife wasn't too excited about dragging two GMCs home at once so I passed on it. I'm not sure I have seen an 860 for sale since. And I had agreed to haul a dump truck out of Kentucky for a friend of mine. At the time all I had was 45ft flatbeds and I probably would have run out of room. I now have a 53 foot drop deck to haul my toys around with.
https://photos.app.goo.gl/sCmPus18AR2uRgww7I have heard about 860s being produced until 1962, but I never have seen anything to confirm that in any of the GMC parts books I have. I really think the B series replaced it in 1960, but that is just a theory.
