Technical 6" oe fit?

Would love to swap these wheels out with four used chrome 15x6 oe wheels available locally, cheap. Ideally wheelsmith big/littles would be perfect but logistics to Canada are outta sight.
Rubber is 8.20 15 slicks with a recommended 7-8" wheel width. And 560 15 vintage bias ply with recommended 4-5.5" wheel width. There are old threads with 6" wide wheels on 8.20 vintage "treaded" tires (Moriaritys 40) but not the cheater slicks.
What do you guys think, 15x6 ok? Thanks!

 

I'll just peel this off of page 5, see if anybody can help. Thanks

 

I think you should be okay. Not that far off of recommended widths. Break them down, and mount them up on the 6" rims.

 

the 8.20,s no problem at all. The 5.60 might be pushing it. I have 5.60's on 5 inch rims on the front of my 39, there not bad but i wish they were 4.5 or 4 inch just so the side wall doesn't pull out as much. 6 inch is really going to show how far out the tire has to stretch.

 

what are they going on? the chrome steelies that is.......