Hello Tim
That is a great little truck with the auto trans and 22re. The overdrive is in your transmission is a lot higher than the 5 speed stick. I would go with the 488's for sure with 31 or 32's.
The V6 trucks with auto trans and 31's came with 488's out of the factory. Your 22re has more bottom end power than the V6 so stick with 488's.