What specific cam should I use to help push those tires?

If the diffs are still geared with the stock gears, no amount of power adders you install will do much.  The 35's are 20% bigger than the 28's, this results in a 20% reduction in performance.  If the PO regeared to 5.29's, a crawler cam from enginebuilder.com would likely be the better overall choice, a header might also be worth it, just make sure to go with one for lower rpm performance.

If you do rebuild the current 22r, I would go with a performance rebuild, it wont cost you much more than a stock rebuild.  Take a look at the enginebuilder.com site, using their components you can build the 22r to about 145 reliable/everyday usable HP.