DIY Gen III to Gen IV LS Bench harness for E37 PCM

A Gen 3 LS bench harness is super cheap online, but it doesn’t quite fit my engine. So, how easy is it to convert a Gen 3 LS harness to a Gen 4 E37 (4.3 Vortec) PCM harness? ALL WIRING DIAGRAMS AND PIN OUTS WERE SOURCED FROM: https://www.customecm.com/home They have tons of helpful info, products, and are also based out of my home state, Oklahoma. Support them if you wanna