The Tilt Cab G.M. COE's of, 1960-mid 70's(styling stayed the same)are not as "Rare", as the earlier COE's, but, they're numbers are definitely dwindling.The Chevrolet version, is a little more "rare", than the GMC version. And if you should happen to find one of those V-12 equipted GMC Tilt Cabs, you'd really have something. Alot of them, were used as, straight trucks, for textile mills in my area, & alot used as Fire Trucks, & dumpster trucks. Check out
http://www.6066gmctrucks.org/Lmodel.htm , for more info., on them.