With 32's could go with Toy 4.30's or 4.88... (if your is 4.10)
These could be found in junkyards or ebay - easy dropin's not terribly expensive - if you have time to look for em (4.30's are cheaper & not as rare as the 4.88)

Ups & downs.. the 4.30 will probably most likly be a 2-pinion (4cyl) the 6cyl is a 4-pinion (stronger <- but what are you doing with the rig?? Hardcore???) 4.88 (fact are usually 4-pinion) may find someone who has regeared (changed out the ring & pinion)

5.29's are another option (usually a regear) but unless you plan on 35's+ I wouldn't worry...

Heres some Diff Info

Can look up by VIN HERE but remember someone could of swapped to something else....