speedo.

donjohn · #1 (**permalink**) 05-03-2002, 03:55 PM

I have a C6 auto and 8.8 rear axle. I`am putting a 9" currie housing in with a 350.1 ratio what do I have to do to get my speedo to read correct it is pretty close now but the 8.8 has 273 ratio thats why the change thanks.

dscott · #2 (**permalink**) 05-04-2002, 07:45 AM

donjohn, You need to check the speedo against a car with a known correct one. Find out how far off it is up or down. Then you need to remove the gear from the trans, count the teeth and add or subtract for the proper speed. Each tooth is about 4mph. More teeth is slower, less is faster. The max number of teeth you can have is 21. Good luck! There is also a formula for calculating the number of teeth but you need to know if you have a 6 or 7 tooth drive gear in the trans.
Don

Jack21 · #3 (**permalink**) 05-12-2002, 06:05 PM

Company called ACI Engineering in Portage, MI makes speedometer cables and ratio adapters for virtually every application. Reasonable prices too. (616) 327-1991. Unfortunately, no web site.