Thought I had found a 71 K20 in Dark Yellow, it isn't. Review of the SPID shows it to be a 71 Ochre Custom /20 on, apparently, a K10 chassis. Haven't seen the frame numbers but the seller intended to look for them.
Might be a nice builder for someone, considering it has an A/C cab and a wood bed.
http://cosprings.craigslist.org/cto/5867516821.html