Some final data on these gears. The usual YOU ARE RESPONSIBLE for you own work and research applies. Not real hard mod to do though, just be thorough.
2008 2.7L reg cab manual 5 speed has the gears off the transfer case on the passenger side. The TTORA data mostly works for this transmission, but it supports gen1 mostly. My stock gear is a 29 tooth, yours might vary.
I bought a 30 and 32 tooth gear sub assembly. My suspicion that the 32 wouldn't work, was right. It wouldn't go in because its too large, the inner worm gear can only work with a certain range of teeth. This appears to be 27, 28, 29, and 30. Gears are around $25
The stock parts have a stat saying n=29:11 , or n=30:11. There is no 31tooth ..... then it goes to N=32:13. I'm not going into the x-fer case to swap further, I'll regear further with 235/85 r16 or 265/75 r16. Those are both31.7" tall.
29t to 30 t yields a 3.5% speedo correction.. 4.56 gear swap incurred 11% change roughly.
31.7" tire will yield approximately 4.2% , totaling 7.7% of 11%. It'll do just fine from there.
The link above works fine for swapping the gears. Simply locate the speedometer unit, unbolt 12mm bolt, pull out unit. Its a precise fit, but not too tight. Pull the retaining clip, gear slide out . Reverse process to reinstall, use new clip and GET in the GROOVE, use the new gasket too, old might rework, I didn't try.
Tire data for a stock Tacoma w 4.1 gears & 245/75 r16 setup.... usual Tacoma speedometer error won't apply in this math.
After 4.56 swap with stock 29T, 60mph on the speedometer = 50mph on gps, after 30T 52.6 mph
after 4.56 swap with stock 29T, 40mph speedo = 33mph , 34.5 mph with the 30T.
.....20 speedo was 16 w 29T..... 17.5mph w 30T.
What I don't know..
6 speed manual, it might be the same, might be on abs.
would a 31 pressed on to a stock shaft work? no idea.
Is this worth doing for you? maybe not. If the speedo remains innacurate you still better monitor a GPS or know how to work the math for speed adjustments. I have no regrets trying. The 4.56 gear and trutrac were worth it, so whats another $25.