In regards to gearing: Yes do it. I have messed with the typical HP adding mods over the years with a 22re and nothing, I mean NOTHING takes the place of proper gearing. Re-gearing to match your tire size will do so much more than any typical power adding mod.
The only exception would maybe be if you swap to a turbo diesel or some kind of V8 which would want the higher gearing realized from larger tires.
