I find the that the PN70 has a bucket load more grunt then the stock silver can motor so that is a big help here. I also think having a rear dampener is a huge help, it is amazing how much you can change the character of the car by changing springs or running different fluids on the dampener and you can combine this with front end mods to have a car which is much more composed than a Box Stock car.
I agree with all that Jim said here, and would add gearing to the list! The PN 64p gearing I use in Stock is more efficient than the stock gear diff, and allows many more gear ratios, so you can better find something that works well with the motor you are using and the particular layout. But its mostly the motor. The PN 70T is much more powerful than the stock motors. But I am running the stock gear diff in Pro Stock and I'm faster than in Stock. LOL I use the KO Propo EX-10 EURUS with all my cars...
Jim, looking forward to seeing what you can do CCW!
Cheers!