What 20's fit on 67-72 with no problems?

[Aarons72]

I am looking for my options for 20's on my 72...What 20's will fit our trucks without having to special order? And what rims will fit without any problems? I'm basically wanting to complie a list of 20's for 67-72's that people can order straight from a catalog etc...and be confident that they will not have center cap problems, backspacing problems or have to have them specially built. The other problem I often see is guys ordering wheels that will fit fine but have the wrong offset which makes them sink in under the fenders too much...then you get spacer issues etc...

Any pictures, model numbers, wheel names etc...would be of huge help for a lot of people.