GMC truck bed - how do you know the year?

[Lefty&Son]

Hi Guys,

I scored a decent fleetside bed here not too long ago, but am not sure of the year. Is there a way to tell for sure?

I can add a picture, but it will be a few days before I can get to that.

Thanks for any info.

By the way, my "score" comes with a price - I'm changing my beautiful stepside into a boring fleetside

Just kidding about the "boring" but I am a little bummed, despite the $100 price for the complete fleetside bed.

Regards,
Lefty