I am looking at correction devices, unfortunately there is no cheap solution. there are mechanical ones with set ratios around $80, but Im not sure they will screw on and there are electrical drivers that are much more expensive but infinitely adjustable and again not sure if the threads are the same. I do the calc in my head for free

__________________

1982 300CD Turbo (Otis, "ups & downs") parts for sale
2003 TJ with Hemi (to go anywhere, quickly) sold
2001 Excursion Powerstroke (to go dependably)
1970 Mustang 428SCJ (to go fast)
1962 Corvette LS1 (to go in style)
2001 Schwinn Grape Krate 10spd (if all else fails)