Did you fill up in Reno? I know when I was running up there a lot my '90 always ran better on the way home, as well as got better mpg's when filling up in Reno. You also tend to not climb as fast between Reno and Truckee as you do from Sac to the summit.

How open is your cat back exhaust?

Assuming you have a 5-spd trans
The 4.88's and 30's is going to put the rpms a bit high, 32's would be a better match.

If the 30's are new, and you don't want to buy bigger tires, 4.56 gears would be a better choice, and would allow you to run 31's in the future and would put at stock ratio for the 31's.

Is Dave'z quote for in vehicle installation, or is the price just installing the gears in the rear third and IFS section that you bring up to him?

Cruising along the trail at 1000rpm's is likely going to require dual cases, or regearing the single case to 4.7's, and then still likely to run a bit higher than that. If you find you are stalling on the trail when crawling, adjusting the idle to about 1500rpm, should help.