'70 C10 Long Bed swap?

I'm looking at buying a '70 C10 long bed fleetside. Of course I prefer a stepside bed. I've located a complete '66 step side bed, all the panels, tailgate, wood floor strips, lights etc. From what I'm reading it does not appear that I can just swap out the beds. Apparently Chevy changed the frames in '67 or thereabouts. Anyone out there know what kinds of modifications would be needed to get this bed to fit the '66?

Joe

 

No offense but you’ll need to post this on the off topic forum.

 

wrong fenders, but other than that it should be pretty close.

Short stepsides look pretty neat, but longbeds...not so much...

(yeah, I made that mistake myself long ago)

 

Will do Chrysler.

I know Squirrel, but as my grand daughter says "you get what you get"