You are correct, would probably "originally" have had all the '92 era gobble-de-gook - before it got transplanted.
A snippet from another source that I found had this info: TND= '92 truck, 350, 210hp, manual tranny, TBI, 10 and 20 series C/K L-05 RPO code
(TBI being throttle body injection)
All that stuff most likely removed and discarded. Basically a 350 long-block transplanted into your '72, with '72 era fuel pump, etc. installed to replace the newer stuff removed.
Hope this helps answer your question???
