Man, with all the time you guys have spent discussing gearing, you could have already re-geared!
Isn't it funny that a rig like the 80, which is as much a "is what it is" vehicle as you will ever find (the base features of the rig will always define it no matter what you do) attracts so many OCD people who are just convinced that they are going to figure out something new?
Hey 7, you need a Blackstone report. Hurry!
I did 5.29's because I have done this before with a large inline six, and I know that as long as you aren't looking for a lot of headroom in top speed (and the OP is not) that the best overall performance will come from the lowest gearset.
With an automatic transmission, much of what you are doing with regearing is setting comfortable cruising speed/RPM at the top end and shifting your typical "dead spots" (speeds where RPM is too low and you are "between gears") between certain mph ranges. These engines rarely thrill with regears when you have a heavy vehicle - it's a tuning exercise (that is not the case offroad, where the gearing leverage in low range really shines).
I really like the lower gears (with 37's, my setup is still about 12% lower than stock, was closer to 17" with 35's) because the sweet spots tend to be well aligned to city/highway speeds typically driven (not cruising much over 70).
I will trade top speed headroom for gearing leverage any day of the week on a lifted rig with big tires, but that's me.
Essentially what I have done with going much lower is eliminated about half of the OD reduction, which is good, because on my rig OD is too highly geared for where I live. That also means my best fuel economy cruising at "normal" highway speeds tops at 70 mph and I lose 1-2 mpg by trying to cruise 70-80 mph.
At 65 mph, I regularly achieve ~13.5 (tuned Scanguage readout). Not bad for sticky 37's at high altitude on trips where virtually nothing is flat.
How painful was it with your 37's on your '80?
