Need advice after re-gear

[chefdab]

I had my LJ re-geared about a week and a half ago to 4.56 with the 35" tires. The shop put in a 35 tooth speedo gear. Now when I check most of the online sources for which speedo gear I need, they say it should be 37 tooth. One chart even claims to be GPS verified with that speedo gear and my diff gear ratio and tire size. The stock setup was 3.73 gears, 30 inch tires and a speedo gear with 34 teeth. When I got the 35 inch tires on the same 3.73 gears, I had a 29 tooth speedo gear. Now when I crunch the numbers and do the math my self, I keep coming up with 35.6 tooth gear. Now I know I can't get a gear with half a tooth so should I stick with the 35 tooth or round up to 36 or follow the charts and get a 37? And if the 35 tooth is in fact too small, am I reading more or less miles than actually traveled? I want this to be as accurate as possible. I would like to see if my mileage has improved any with the re-gear but I can't do that if my speedometer isn't accurate. Thanks.

[moneypit]

When I regeared I followed the chart. I tested my speedo against my wifes car on cruise and it was dead on.

[jeepnut]

Interesting point. With the stock tires gone, now running 33's, is my mileage different than what os shown on my odometer?? I have figured out the speedo gears.

[Skull]

One thing to keep in mind is that tires may say 33" or 35" but are not exactly that size. Some 35's maybe only 34.4" tall. I put a Superlift Truspeed speed sensor calibrator on mine and used a GPS to set it. So when I go to 35's I can just adjust for the difference.

[chefdab]

According to Tirerack, the actual diameter of my 35" MT/Rs is 34.8"