As far as MPG, mine has seen a wide range. I have a similar truck, 88' 2.3L, 5sp, x-cab, ??? rear end (I know it is 7.5"). When I first got the truck about 1yr ago it was only getting 17MPG avg. After many std service repairs, plus a new trans, new tank, fuel filter, and too much to list it runs great. Some stuff covered here: (cleaning the TB and intake was a big help)
https://www.ford-trucks.com/forums/s...d.php?t=248941

Now I get MUCH better MPG. I only drive 10 miles to work, so it is mostly city/stop-n-go driving. 23-25MPG city, 25-27MPG hwy. Oh, I forgot to mention.... 115k.