What valve springs are on the heads. If the heads came with roller valve springs and your using a hydraulic cam then the lifters may be colapsing because of too much spring pressure.
The digital-6 ignition will run like junk if the magnetic pickup wires are reversed.
If you have not degreed a cam before, you may have used the first lifter bore when degreeing the cam?
The first lifter bore is the exhaust lobe, not the intake lobe, so if you did this the cam will not be installed correctly. Double check the sparkplug wires firing order. The order on the cap is counter clockwise.