Does anyone know which speedo gear I need for 3.50 gears, C-6, and 33 tall tires.

 

New speedo gears aren't only based off of your current tire size and final drive, they're based off of how much of a change you want to make.

For example, if your current speedo gear has 15 teeth and your speedometer says you're going 70mph when you're really going 65, then you go:

(70/65) * 15 = 16.15 so you'll want a 16 tooth speedo gear to put it back in place.


Either get a GPS to see how fast you're really going compared to what your speedometer is, or time how long it takes you to go 1 mile when your speedometer says 60mph.


The other way to do it is to compare your current setup to what was originally stock on your vehicle, but you have to know what it originally came with as far as final drive and tire size.

If your final drive hasn't changed, then it's just a matter of the tire size difference. For example: If your old tires were 31" and your new ones are 33" and your current speedo gear has 15 teeth, you would need:

New number of teeth = (Old Number of Teeth) X (New Tire Size) / (Old Tire Size)
NNoT = 15 * (33 / 31)
NNoT = 16



*Note* If your final drive has changed as well, that'll need to go into the equation too.

 

where can I get these gears and are they easy to change. And thankyou for the reply.

 

I haven't changed mine yet as I am still looking for the tires I want and the gears I want to go with, but I believe bronco graveyard has them.

 

Sorry. The idea is right, but I was running on 4 hours of sleep so I got the speeds backwards.

So it would be

(77/65) * 15 = 17.8 (18 tooth gear)
(37/31) * 15 = 17.9 (18 tooth gear)