79 CJ5 wheel size

I am trying to match the wheel for the spare with the ones that are on there.

The ones I have: American racing "5034"

question is, what is the backspacing. (I measured 3.5" but I am not sure how to measure the backspacing)

Is there a place where I can look up that rim and see what the actual backspacing is ?

I tried that, I can't find it there (it is a wheel that is older than

I measured it again though. it seems to be 3-5/8 back spacing. I can't find any wheels with that backspacing. I see lots of 3.75 backspacing and figured that teh wheel sticking out 1/8 of an inch for a spare is not a real big deal.

An 1/8" is just relevant unless you are tuning a Formula One racer. And many used rims are up to that distance out of round sideways.

Yours is probably a measur> >>

Interesting, I just talked to an 'American Racing' dealer who said I should measure from the mounting surface to all the way to the outside of the rim.

but as I said, it's for a spare. I happened to get my hands on an almost new super swamper (exact same as I run) less then a 1000 miles nubbies still on it for a really good price. Having backspacing off

Shrug. Your dealer is doing the conventional wisdom. Except that with that method you cannot compare an aluminum wheel back space to a steel wheel backspace and get the same amount of tire clearance.

I did some work comparing racing rims for a Porsche GT-3 Cup car, the critical dimension varies quite a bit between brands. Which changes the 'measured' back space. On the race cars, a difference of 18" to 1/4" can mean the difference between a shredded tire and good to go. On a Jeep, you just adjust the max turn bolts on the front hubs.

Go for it.