R/C Tech Forums - LRP 8.5 to 21.5 "stock spec"?

Does anyone know the power difference between the standard 8.5 LRP Vector motor and the 8.5 Vector Stock Spec? The Stock Spec 8.5 is 4700 per volt, I believe the standard is less than that. Also, the stock is rated over 300 watts, the regular 8.5 is in the 200s. Why would the stock spec be more powerful? You would think they would regulate it more.

http://www.teamassociated.com/lrp/new/x11_page.pdf

Also, has anyone else had problems with 8.5 Vectors? I have TWO purchased 3000 miles apart that both have the same problem--they stutter like hell to the point where the car is undriveable. Its not the ESC as I have a Novak 10.5 that runs perfect on the same Sphere comp. I have tried everything--different rotors, different sensor wire, different timing, checking an re-soldering connections--still stutters. I missed the mod truck main on Sunday because of it. I think there is a bad batch, anyone else?