Some things to keep in mind. 32's are an oddball tire size. Likely hood of someone having a spare ( incase you have two flats on the trail) are slim. If you're going to go with 32s you might just consider going with one of the narrow 33's and doing some extra work to clear them. They have less rolling resistance then the 32's. (9.5"-10.5" as opposed to 11.5")
Generally speaking though, an AT will usually be around .5-.7" shorter then advertised. Although this really depends on your choice of wheel. A tire will be taller on a narrower wheel because the sidewalls are pinched inward. So if you put a 12.5" tire on a 8" wheel and a 10" wheel, it will be taller on the 8". (be aware narrow tires don't like wide wheels.) This also means you'll have to run less air pressure since the tire acts like it's overinflated.
Mt's generally run closer to the advertized height. Usually .5-.3" shorter. This does get a bit cloudy when you throw in Interco into the mix. Their bias ply tires tend to be oversized on many of their tires. My 34.9.5R15 measures 35".
