Has anyone got a link to a good diff ratio/ rpm/ speed calculator? Or anyone good with this type of maths? I'm thinking of swapping the Jag diff on my van in order to get some more top end cruising speed out of it as it's revving out before 60mph now. It's a 3-litre V6, 4-speed manual...

http://www.4lo.com/calc/literstocid.htm

Hi all, I found this earlier, and thought I would pass it on !.:bigsmile: http://www.ringpinion.com/Calc_GR.aspx Hope its of some use. Thought I would add these Others for Good measure !. http://www.ringpinion.com/Calculators.aspx Dave. :tup:

Just found this, may be useful if you fancy changing diff or tyre sizes http://www.ramblerman.com/blazer/gearcalc.htm