Mine is nearly stock 1 rebuild .030 over, not certain what was done internally by the previous owner. It is very well tuned by me using a wideband 02, has electric fan, HEI ignition with MSD coil, Single exhaust no cats and all the smog BS removed. I get 13.6 on the highway <70mph. If it is getting 14 that is likely the best it will ever get. Aside from an overdrive swap, fuel injection, and performing other things to reduce wind resistance. Mine is on a 4" lift and 31x10.50's with tow package 3.31 gears. Check under it you can read the tag on the T-Case and verify its an NP229 case. All the 90's I knew of were 229 equipped. It should have the 2wd/4wd slider switch at the bottom of the dash on the right side of the steering column. Then a high/N/Low flag shifter under the driver seat against the trans tunnel.
06-Corvette z51-6spd,b&b,K&N low miles.
77-Corvette Stingray 496 BBC/TH400 built 667hp+
00 WJ 4x4, 4.7 stroker, turbocharged,..lots more..
01 WJ 4x2 4.7v8 Limited (needs valve job)
90 Grand Wagoneer 401 Edelbrock Heads, Lunati .510/.527 FT Cam, Edelbrock RPM Air Gap, Holley HP 750, Thorley Headers, HEI, Electric Fan w Digital controller,4" lift 31x10.50 Goodyear Duratrac's on Pro-Comp Wheels,new interior, seats,seals,Alpine and JL full system, Remote HEI, Clifford 2 way with remote start,windows,tailgate.
96 Cherokee Country 4dr/2x2 White/Tan 3" Lift Sahara 18" Wheels 32.5"'s 99up head and intake- for sale soon!