Sir,
If you are close to Griffin, GA, there a junk yard OPPS I mean Auto Salvage Yard, they may have what you are looking for. I think the name was Andrews, but not 100% ( I have CRS sorry) I found then on car-parts.com. I was last month and they had F100s & F150s from the 80's. The prices were very good ie cheap. I hope to go "looking" this weekend and will keep eyes open and let you know if I find anything.
Georgia
1982 F100
300 6cyl
43,000miles
Work in progress