hey Bob! seeing these guys recommending the "universal" aftermarket kits, I just gotta add that not only will an OEM style repro harness [identical to original] fit in your truck the way GM designed it to, using all the original clips/holes/grommets in the original locations, but every wire except the tail light wires will be the correct length with the correct ends already attached .... and have the proper cable wrap already on
and that's first hand experience from someone who has rebuilt a couple TF trucks' original wiring harnesses to a safe, functional stage, installed a couple original style repro harnesses, and spent uncounted hours re-doing the "Painless" universal 21 wire kit in a friends 56 panel so that it fit
close to factory ... except for not being wrapped at all, but requireing a big pile of 'zip strips'
go original
Bill