Just worked out the final gear ratio of the Mi3.5 with that pinion and spur, it comes to a ratio of 6.41
As I said in the other thread to Lee I am currently using a ratio of 5.9/6 ish. So you could try going to a 26 or 27 pinion, so long as your motor temps are ok.
I'm going to pm (as im not sre what we can and cant post) you with some useful resources for working out the ratio and setting your car up. To be honest though your car looked really good yesterday and was very fast
