I assume you ment a 7.50 x 14.(I don't think they ever made a 7.50 x 15) Acording to the tire chart on Coker's site a 7.50 x 14 is 27.02" in dia. A 7.60 x 15 is 28.66" in dia. Acording to that chart for 57 to 65 they did make a 21 tooth gear, it's gray. 2204355 16 teeth - 2204356 17 teeth - 2204357 18 teeth 2204358 19 teeth - 2204359 20 teeth - 2204360 21 teeth Brown 16 Teeth, Orange 17 Teeth, Purple 18 Teeth, White/Tan(HD) 18 Teeth Blue 19 Teeth, Green 20 Teeth, Black(HD) 20 Teeth, Gray 21 Teeth Dan Don H. wrote: > > I don't know how you'd get tire height from the original sizes, but > according to my 65 FSM, a 7.50-15 would use a 19-Dk Blue with 3.55 > gears. A > 7.60-15 would use 17-orange with 2.93:1; an 18-Dk Purple with 3.23:1; > and > 20-Green with 3.55:1 gears. ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html.