Yes, SC default is 31.5 on my truck. It seems exactly right on now when set to 32.

 

Well I'm sort of releived that my default is 30.5 because that's what they measured with a ruler...I thought I was going nuts! Most everyone doubted my measurements saying it was suposed to be 31.5 which is what my new tires are. I never changed it from default yet, and it still reads close to 2000 rpms (maybe 1900) at 70. But I think it's off around 40 which use to be close 2000 rpms at 40 in second, I think? No big deal though, I may bump it up to 31 later on down the road, I'm tired of messing with it for now, lol! I learned my lesson the first time sweating my *** off tuning it. This time I used a metal folding chair and loaded it from the outside with a cool breeze blowing!

 

my old truck, and new truck have the same problem. I just played with it a few times, each time increasing or decreasing the size by have an inch till i got d@mn close. only took a few times

 

well 2 school zones and 1 constuction zone later and the magical number is 31.75 sooo anyone with 33 inch toyos and a superchips or diablo thats your number case closed !! thanks guys now i dont have anything to complain about with my truck shiiit actually still need the 3.92s

 

With my default at 30.5 and my new tires measuring 31.5, what do you think my magical number should be...am I close? I haven't touched the SC settings, it's still set at the default settings. And about your gears, I think you would be better off with a 4.10 with 33's if you're going to buy a new set. I wish I had a 4.10 instead of the 3.92 and my tires are 2.5' shorter than yours.

 

really ?? cuz i am definitly moving up to 35s soon i have a detriot tru-trac system going in at the same time due to mopars trac-loc system having a high rate of failure around 90k but i often hear that with 4.10s you top end falls off alil which i dont see how its tru when every time a mess with a 5.7 Tundra i get smoked cuz of their 400hp fed thru 4.30s

 

If there was no wind resistance 33inch tires with 4.10gears at 5500rpms you would be going 196.6mph in topgear .67 overdrive. So unless your going to be competing in Bonneville,I dont think you need to worry about losing top end. If your moving up to 35s, then 4.56gears would be a good choice. Hope this helps.