The 80 -82 front ends are different. However the fenders 80-86 are the same so the 83-86 corner lights will bolt up. The difference is 83-86 had a different grille and the corner lights are made to match at the bottom part of the grill. If you bolt those on an 80-82 front end it will look funny. I have an 80 and updating to the 83-86 front end.
Check here for parts:
http://www.nissan-auto-and-parts.com/bodyparts/pickup.html