Hi everyone. I hope you had a good turkey. Please were can I get the gear I think I need to correct my speedo after I installed the 4:10's. in my 97 4.6 windsor and a auto trans. 2wdr. Which are great by the way except for a little vibration that feels like the driveshaft starting around 80 85 and staying all the way up past 100 plus. Here in Vegas my Ford Parts guy said that they don't have a 23 tooth gear and that my speedo would need to be calibrated at the dash. I find this unlikely what with the info I,ve been reading here. I would appreciate all the help you guys can give me and I'd to thank you in advance.

Mine is the L'il Red Truck..Thanks again

 

Go to a local speedometor shop. Here in Tucson I had mine speed checked up to 85 mph. They gave me a chart with speedo read out and actual speed in 5 mph increments. With my new tires I was about 1 mph off.
I bet they will have or can get you the correct gear.