what size tires would fit on my 89 bronco II with no lift?
The bigger the better
i'm getting a lift soon but i want some bigger tires for may long

 

I'm running 29's on my '87 with only the tiniest amount of rubbing. I've put the 31's from my explorer onto my BII, and they did ok, but they did rub when the suspension flexed. The usual concensus is 29's are the biggest without rubbing. running anything bigger will be matter of experimentation and how much you can tolerate rubbing.

 

31's do fit but, you will need to do a little bit of cutting to the inner fender. Other than that you should be ok with 31's.

 

29s or P235/75r15s are the biggest without a lot of hassle that would be plug and play. P235s on the regular rims will give you about 12 inches under the transfer case skid plate without airing down. This is good enough for a mild romp through the woods and fields.