I picked up a hood for next-to-nothing today, couldn't resist grabbing it to make the mockup more complete
It's an early 76 hood, you can just barely see the small notch at the bottom edge near the front, I have no idea what that was originally for.
I've decided I'll be mounting the spare right behind the cab, parallel to the back of the cab, it's really the only way to store large spares in this bed. I'll recess it in the bed floor a bit with a well I'll make from a large trailer fender.
Here's a quick mockup photo showing the fender serving as a well, it's got a 36" radius and it is 13" wide, so the 32" tire sitting in it looks small. The well will go about 3" lower, and the bed floor, indicated by the stick, will probably be 2" higher than the stick. Obviously (I hope it is obvious), most of the fender will be thrown away, only the semicircle below the bed floor will be used.