GMC_YA_L8R
OBS Enthusiast
I was, perhaps mistakenly, under the impression that the GMT400 and GMT800 trucks had different wiring between GMC and Chevrolet for the taillights. Am I dead wrong on that? I need a decent replacement taillight as one of mine was so brittle I noticed a small crack and pressed it with my thumb and now there's a silver dollar sized hole in it lolI think, on the 800s, that as long as you're changing the lights on a pickup, to another fleetside pickup, they interchange. That generation is where GM decided to start having different taillights for the different styles of trucks and SUVs.
I know the Denali used different tails than the pickup, and the Sportside ones are unique to them. Then the next generation after the 800, is when GMCs start having different taillights than Chevys.