Cold backfire & No power

[scottrob]

I have a daily drive minor moded GT that's backfiring when you first accelerate with any power on a cold engine and was pinging. Now once it's warmed up, it surges during acceleration to a point and then just acts like a few cyclinders shut down and there's really no more power. It has a new Comp Cams timing chain in it, new cap and rotor and wires. I've adjust the timing and things get a little better or worse but still the same problem. The ignition module went bad last year so it's new and the coil was changed at the same time. Any ideas? This 5.0 is accelerating like a 1.0.