I had the same issue with my '65. I simply used a stock wheel and the correct factory size 4-ply tire that I bought from Coker Tire.

Looks pretty cool, the factory size spare vs the newer rolling stock thumbs_up

Here's my '65:
http://i645.photobucket.com/albums/...Status%20Photos/GEDC1242_zpse55aed88.jpg
http://i645.photobucket.com/albums/...Status%20Photos/GEDC0535_zpsc951c34d.jpg

And as Denny stated previously:
Originally Posted by Denny Graham
Why you guys always gotta re-engineer this stuff. It's a spare,,,,, not one your going to run all the time so it doesn't have to be the same as the rest of them. Just get a tire for the spare that's a smaller diameter. Now days you'll probably never have a flat anyway. I taint had a flat since I was 17 years old and that was over half a century ago.

DG

In the Stovebolt Gallery ~~ "The Orange Crate" 1965 C10 SWB Step Side Build Thread

Inspired to be different. Different in a way of my own, not in a way that others strive.