I inherited a 8P nail on my way home

Anyway, I put on my spare.... the stock 235/70R15 on the rear drivers side. The stock tire is a 28" tall tire and the Imp SS wheels are 27". The question is, will the inch difference harm the Posi if I drive the 23 miles to the shop at 55mph? If so, I can rotate the spare to the front.

It will probably be fine, but if you want to make the effort, putting the front on the back is better.

If you have the luxury of a place to park it, you can get the tire replaced on the rim and reinstall it without moving the car.

If it did not ruin the tire...did you try removing the offending nail, and use a plug? A plug should work, and you could go to the nearest gas station for some air. You could even do it on the car, if you have an emergency punp.

Put the spare in the front. It's cheaper than wearing out the posi.

If you get a flat in the rear in this situation:
1. Jack up the front of the car FIRST and swap the spare with one of the other good SS Rims.
2. Jack up the flat tire and replace it with the good SS rim.
3. Drive as far as you need to.

Yeah..I would not drive 23 miles like that. I made that mistake on my Fleetwood back in the day. Just my 2 cents.

You might be fine....but why risk it since you can swap?

That is what i did. sort of..... At 4am, I decided that I didn't want to risk it, so I jacked up the front, mounted the flat (with 3 lugs), replaced the rear with the front, then put the spare up front. God I love air tools!!!

tire fixed and all is well again.