Just an update: got the trans adjusted to shift much better. Also, I ordered a new fan and clutch for it, and I am going to ditch the Auto Zone fan clutch. With the better shifting on the trans, going up to Overdrive sooner, locking up sooner, and all around generally shifting better, I averaged 23.1 MPG this time around (556.1 miles / 24.081 Gallons = 23.1 MPG). This is once again in mixed driving (some highway, but not interstate, and some around town and stop and go), with the A/C blasting front and rear (it has been sweltering hot, in the mid to upper 90s all week, even up to over 100 as it is right now). Under these extreme conditions, I have found that sitting at idle, the temperature creeps up. It usually runs at 190 degrees now that I have a 180 degree thermostat, but with both A/C units running and sitting for an extended period of time (more than 5 minutes) it will creep past 210. If I idle the engine up slightly in neutral (probably about 900-1100 RPM), it comes right down to about 195-200. Also, if traffic starts moving even a little bit (15 MPH) it comes right back down. I think my electric helper fan (to be installed this week when the new fan and clutch arrive) will be just the ticket to keep her cool when it is broiling hot outside.
1993 Suburban 2wd 6.2L Diesel Conversion "Andromeda":
3.73:1 gears, THM 700-R4 transmission, and
J-code 6.2L diesel from a 1984 C2500 Suburban
1996 2wd to 4wd converted Ford F-150 300ci Inline 6 "The Argo" 336,000 miles and climbing
1992 Caprice Wagon 5.0L V8 "Enterprise-D"
"Ah ha ha ha! I swear! Tractors is so dumb!" - Mater
"The Argo? That ridiculous pile of scrap metal!"