To figure out the equivalent is easy.
84/64=1.3125 (this gives us the ratio between the two pitches)
96t 64p spur - 96x1.3125=126
51t 64p pinion - 51x1.3125=66.9375
Just remember gearing changes by one tooth either on the pinion or spur are much smaller using 84 pitch.
For 64pitch changing one tooth on the pinion gear changes the FDR by .0715
(96/51)x1.9(xray IR)=3.576 FDR
For 84pitch changing one tooth on the pinion gear changes the FDR by .0541
(126/67)x1.9(xray IR)=3.573 FDR
And yes they are on the website. I just ordered a bunch of stuff. Just wish I could have them before this weekend!
Here is an equivalency chart EA posted on Facebook.