For a perfect stock match for 315's you'd want 4.48 gears. So you would be .40 more (lower) than that with the 4.88's.
with 37's a stock match would be 4.79 gears, so 4.88's are a near perfect match for 37's if you want a stock feel.
I really like how my truck is feeling with the new 37's combined with the 4.88's I've had in the truck for a while. Shift points seem better and it corrected my speedo (within ~1mph of my GPS). Feels good and the slightly lower highway rpms are a welcome thing. Personally I prefer having a slightly larger pinion gear. I know there are plenty of people that run 5.29's without issue but the smaller pinion gear can become a weak point.
If you still wanted lower drive ratio, if it were me, I'd do 4.88's with 37's and then consider lower tcase gears for either the high or low range or both depending on what you're after.
Now you tell me....
Just kidding, I’ve had 5.29’s, Axles, rebuild kits etc sitting in my garage for almost two years. I just finally got around to getting them set up.. I’ve got some 35’s that are beyond their lifespan currently. I’m on the fence on tire size still, my brain/wallet are telling me 37”s but the kid in me really wants to give those new BFG KM3’s a shot in 39” which is technically a 38.5” tire..
For what it’s worth - I had them cryo’d and set up by Zuk to try and ensure as much durability as possible....