I recently changed gears in my 71 Cutlass from 2.56 to 3.42 and my speedometer is way off.The tires are stock 225/70/14 (26"DIA.) and it has a TH350 tranny.I would like to know what drive and driven gears I would need.
I tried a formula I seen online but it was alittle confusing.I also heared there color coded.Any help would be apprciated! Thanks... Rudy

 

Well the gears are not color coded they go by how many teath are on them. the best thing you can do is get a speedo gear reduction box. You need to get the speedo checked so you know exactly how far of it is and order the proper gear box. They can be ordered from tacoma speedo in Washington or http://www.transmissioncenter.net/sp...n_______va.htm. Tacoma speedo can build and ship same day I'm not sure about the other guys. I worked at the only speedo shop in Seattle and have done this convertion several times vary easy just remove cable casing from the speedo snub and the box goes inbetween the snub and cable.