cam choice.....

Isn't that Purple cam rated at [email protected]?
I will assume you want a bigger cam to go faster. This is a problem since you lack compression for a big cam.
Try a slight smaller cam for increased torque to better power the car throughout the entire run rather than waiting for it to come in. Use as much lift as the heads will tolorate before they stall.

Second issue is lack of converter. At 3K, it is not enough for the current cam. This the other reason to drop in cam size. A cheap and easy way out is a set or Rhoads lifters. Try them. They can take up to 10*'s of duration out of the cam with the proper preload. (Possible pushrod length change.)

You also failed to mention gear ratio, tire size and the cars weight.