What is the largest lift of cam I can go with and still make the computer work right I'm building the motor with I just wanna get a nice idle and make some extra power it doesn't need to be killer if someone has any help at all that would be great (:

 

The ECM computer will work best with a flash tune, even on a stock engine. Any cam other than stock practically guarantees a need for tuning. You will likely want an SCT tuner and programming by Flying Ryan or Hemifever.

Do not expect your engine to run well with a cam and no custom tune.

 

You can't do that much with lift on stock valve springs.
Most will just do H&S1.7 Roller Rockers.
If you're upgrading so everything works happily together, then something like a Comp Cams 20-744-9 will be nice.