it puts you right in the heart of the power band and actualy holds you there for a brief moment for a killer launch, better have some traction

 

The roots/screw blowers are nothing like the ATI style. They don't peak, and they don't have weak spots really. Maybe a better way to describe it is, tkae your stock truck, now add roughly twice the power all around.

There is nothing peaky abou tthe roots/screw except when the throttle hits the floor it peaks and slams you in the seat!

 

I am not saying that a stall or larger cam will not help a stock truck with a roots/screw blower. A stall will make a vehicle 60ft a hell of alot better. However, after that you don't want the motor out of its torque band when you are going down the big end. I am saying that a 3000 or 3200 would probably be the most I would go.
The stock cam leaves much to be desired, as far as performance. A larger cam would help but, I think anything over a 218/218ish cam would be a waste with the screw/roots blower. Just because a motor keeps making Horsepower dosen't mean it will accelerate the vehicle better than when it is making TORQUE. I would give up 50hp on the big end for 50ftlbs at the line. This is even more important when dealing with a heavy vehicle, like full size trucks.
What makes a roots/screw blower so great? Boost right from the start. Why not take advantage of this with a small cam (and by that I don't mean a 180/180cam) and a smaller converter (and by that I don't mean stock).