Correct Bed for a 79 K20 Round or Square

[UNHLAW2016]

Hello, I am not new to the truck thing, but new to the late 70s vintage. I just purchased a 79 k20 with less than 30k original miles. It currently has a utility body on it, and I want to return it to the standard 8 foot bed! I am 99 percent sure the gas filler neck is currently on the passangers side, but that could be incorrect! Did the 79 3/4s have a round fuel filler or a square door?
thanks

 

[CSFJ]

Square door.

 

[UNHLAW2016]

When did the round fuel filler disappear on the 3/4 ton?

 

[CSFJ]

Not positive, but I think it was '77-'78 ish. I had a '79 k10 for a while and that had the square fuel filler door.

 

[J Knight]

73-78 had the round fuel cap with single tanks on the right side.
79-80 had the square door with the single tank on right side.
81-87 had the square door with single tank on left side.
On a side note the
79-83 beds have a fuel filler neck held on with 2 screws to an inner plate inside the fuel door.
84-87 beds have the fuel filler neck mounted to a plastic cup inside the fuel door.

 

[Don5]

Thanks for that info on the fuel filler necks. I have heard that when buying a used bed, if it has the fuel filler neck also, you want to get it as well.

Are bed bolt holes different widths from the early beds versus the 80's beds? I heard they were more narrow on the 80's bed. But I am not sure.

 

[J Knight]

Thanks for that info on the fuel filler necks. I have heard that when buying a used bed, if it has the fuel filler neck also, you want to get it as well.

Are bed bolt holes different widths from the early beds versus the 80's beds? I heard they were more narrow on the 80's bed. But I am not sure.

Yes, get the filler necks and hose if its available.
I believe all the bed bolts are the same from 73-87.