You didnt' really see TBI in GM trucks until the late 80s. I want to say 1987? Before that, you would have what I think they called thermotrash, err thermoquads, which were a feedback carb. They had an enrichment valve and computer controls. In the early 80s, I believe it was just quadrajets. Good luck finding one of those sloberjets working correctly, with the shafts not rattling in the housing. Your best bet, would have been an early 90s GM pickup with the 5.7L/350 TBI. Yank the engine harness and ECM, and you would have been golden. Other than throwing a new distributor unit in the thing(the weakest link to the design), it would have started and ran, no choke, no rods to jack with in the carb etc. They didn't win horsepower races, but without swapping axles out on your KJ, you can't have a lot of power anyways.