Here's my take with the math:
Toyo Open Country M/Ts run right at 37:
37"/33"x3.73=4.18 equivalent gear ratio with 37" tires to get stock tire/gear ratio. (still pretty close to a 4.10 ratio)
I'm currently running a 37 that measures 36.7:
36.7"/33"x3.73=4.14 (a lot closer to a 4.10 than a 4.30)
Just for chits and giggles (as brought up earlier) a 36.3 BFG All Terrain:
36.3/33x3.73= 4.103 (hmmm... 4.10s anyone?)
Plan ahead for the variance in tires you might run, not just the set you have on there right now. What happens when the tires start to wear? Your Toyos probably started with a tread depth of 21/32nd... when you lose let's say 6/32nds of tread depth (and the tire is in effect now smaller than a 37), the 4.10s will still treat you better than the 4.30s.
Now the day to day... I drive a mix of back roads and interstate, but I hate having the truck screaming at interstate speeds. 70 on the interstate is fine in theory when talking rpms, but what's your driving style? I'm in a state where 70 is the posted limit, honestly I'm usually 5-10 over that, probably more sometimes since my speedo is so off. I still think the 4.10s are the best bet all around if you're sticking with 35-37" range and have a heavy foot.
I've got trucks from 3.73s on 35s to 5.13s with 44s (rarely sees a paved road) and a 450 on stock tires with 5.38s that never sees the interstate so I don't have to shoot myself.
BTW, if you're that concerned about drag racing, 37s and mud terrains are not your friend. Sure, it's fun to blow someone's doors off on occasion, but let's be realistic it's not going to be a dedicated track queen... that's not what this set up is known for. Most mud terrains have chitty speed ratings anyway. Your Open Country's are probably Q (rated up to 99 mph). Just sayin...
