ok i installed 4:11 gears in my car about a month ago.. they work good and i like them a lot.. anyway now this put my speedo off by about 25 mph.... i have the ohh so powerful LO3 engine and with this power house of a motor i got a govener(sp?) well the problem is the car shuts down at like 70 mph and i need to change my speedo gear... i have the 700R4 trans and my speedo is not digital...can anyone tell me the part number of the speedo gear i would need from stock 2:73s to 4:11s.... any help is great thanks all
Corey

 

I can't give you the part #'s, but check out this site http://www.tciauto.com/tech_info/speedo_gears.htm. You need to know your rear wheel diameter; fill in the other info. You can try assuming the 17-tooth red drive gear (which is what you probably have), but with 4.11's, it likely will give you a driven gear that isn't available. You'd then have to try a different drive gear as well. The available gears are in the chart futher down the page.

After you come up with a viable combo, take the colors/teeth counts to a dealer or tranny shop, they should be able to get them for you. That's what I did.

 

I just installed a 15/45 combo in my car. I believe that's about as close as you can come. According to the counter guy at my local gm dealer, 45 is the most you can get. I'm still about 1 or 2 mph fast as far as I can tell, running stock 245/50/16 tires. I didn't keep the part #s. You may have to change the sensor to use those gears, if so, it isn't cheap. Where the wires plug on is either white or creme color, and mine had 34-38 #s on it. That would be the correct sensor, as they make at least 2 differant ones for f bodys.