I have never built hybrid, 79coyotefrg is the hybrid master. I have a stock 20r in my 80 right now. It has stock 4.37s and I am pulling 35s right now that were intended for my 4runner. It is OK but I never ever use 5th.
With 31s the speedo is dead on ad I can get 20+ mpg, still use 5th on flat highway. It does well loaded down and towing with 31s as well. I like to keep 31s on that truck otherwise I would re-gear it.
I really think with the 4.88s and 31-32" tires if you have your engine tuned up good it should do OK. If you get that 150 horse hybrid going you should tear up the highway with 31s on... I would really consider running 31s for your ride. The slight gearing advantage and the fact that they are more commonly stocked than 32s would be handy for a live in it type expedition truck.
My other rides over the years were mostly 22re with 5.29s and 33-35" tires. With 5.29s and 33s pulling passes was no problem at all, probably better than stock with stock tires. 35s and 5.29s feel about like a bone stock truck.
Oh and adjustable cam gears are really neat. That was the most noticeable mod I ever had on a 22re. I used it with a DOA 270 cam and after tweaking with the cam gear the truck would lug down so far while crawling the tach was just bouncing of the bottom.
