[Dombrasky]

I've always used this http://durangofansite.com/main.php?v...0&page=gearing
... at the top FDR says 7 for a 13.5 motor..so on a 75 spur, and to allow for smaller track, instead of 28...try 27, or even 26 if really small track....so 6.96 for 28.....7.22 for 27 and 7.50 for a 26