What year bed is this

[caleb johnson]

I’m trying to add another gas’s tank on the passenger side the truck is supposed to be a 1973 but I think the bed is newer if anyone can let me know so I buy the right filled neck.

 

[nvrenuf]

Gas doors are 78~79+.

I’m not sure what year the tailgate logo changed from centered to the right side but I believe it was around 81.

I don’t know of any other ways to identify the year of a bed.