1964 stepside wheel question

[Pvas580]

So I recently purchased a 1964 Stepside with original wheels 15x5.5 and was looking to go a little larger. Purchased some rally wheels 15x8 with the 9 slots. Believe from a 4x4 circa 70's or 80's. Did a test fit and they seem to wide. The rim lip looks to be just inside the fender lip with little clearance. I have not mount tires yet and wondering if I should look for a more narrow rim? Maybe the same wheel in 15x7 that Chevy used. These are 6 lug and my plans are to use till I swap to 5 lug in a year or two. Thanks for any help.

[Joe Pass]

I have 15-8" on the back of mine....They are a 6 lug Wheel Vintique's smoothie style wheel. My first set had a 4" backspace and like yours the rim was just inside the fender well lip and the tire wouldn't clear. I also had 1+" clearance on the inside/bedside, so I called Summit racing and ordered the same rims with a custom 4.5" backspace for a extra 20.00 per wheel. Now they are centered in the wells

[The Rocknrod]

Back space is the key to proper fitting wheels.

[Pvas580]

Thank you gentlemen!