I have a 77 280 that came with the collapsible inflatable accordion spare and I recently completed a project to replace that collapsible spare with an always inflated newer "donut" mini spare. I bought a T115/70/14 donut spare tire and wheel from a junkyard. It had the correct lug pattern, but the inside diameter was too small to fit over the front brake calipers. It fit OK on the rear over the drums, but wouldn't work in the fronts.

I came up with two options. 1) use that donut spare as is and if I ever had a flat on the front, I could put that spare on the rear and move my rear tire to the front, or 2) I could remount that donut spare tire onto an old Datsun wheel that would clear the front calipers. I chose the latter. There is some related discussion about wheel widths in this thread here: http://www.classiczcars.com/topic/49310-narrowest-stock-wheel/#comment-450080

Here's some pics of the project. Spare as it came from the junkyard:

Then I bought a narrow older Datsun wheel. The one I picked up is a four inch wide wheel off a roadster. You could use a 4 1/2 early Z wheel, or even a 5 inch wide, but I wanted as narrow as possible. Here's the roadster wheel sand blasted:

Markings inside the wheel. 4 x 14 and apparently from May 1965:

Roadster wheel all cleaned up and POR-15 coated. Moved the tire from the original wheel to my new spare wheel. Here's my new spare with to the original accordion spare and at the top is the original wheel from the junkyard that the spare tire came on:

You can see that the donut is a little bit larger in diameter than the uninflated accordion, but it fits into the spare well:

Here's my new spare in it's home:

T115/70 D 14 mounted on 4 inch wide Roadster wheel:

I had to put the spare on the car and drive it a little just to make sure everything worked out according to plan. So I mounted the spare on the car and drove over to a local park as a test. Steering wheel didn't sit straight, and it drove a little wonky because of the large mismatch on sizes between corners, but it worked just fine for emergencies. And even though it's a little embarrassing looking, here's a pic for proof:

Thanks for doing the write up on this.   Looks to be an excellent alternative to the original spare. 

Thanks for posting all the details.  I've often considered going with a "mini" spare on my '71, but never got around to it.  you saved me a lot of trial and error  

Dennis

Yeah, I'm very happy with the way this project turned out. It's a lot easier of a project if you're willing to use the donut spare "as-is" and accept the hassle of dealing with switching two tires in the event of a front tire blowout. The offset of the original donut wheel is very wrong, but again... Emergencies only.

Dennis, I'm not sure why you would bother with a mini-spare on your 71. I'd love to run a full sized "regular" tire back there, and the only reason I went through all this work was because I can't due to the reduced tire well diameter on the 77/78's. If I could have run a normal tire, I would have never taken on this project. Why are you wishing for a mini-spare?