[Keller]

This behavior sounds a lot like the firing order being off.

I realize you stated that you checked it extensively; not doubting you. Perhaps the module is wired with the wrong trigger wire order?

What I would consider doing is:
- Unplug the fuel pump at the tank.
- Try to start the car. It may start breifly, but will die.
- Get three noid lights for the plug wires, or just use an uninstalled plug in a wire end and somehow connected to ground for each of the coil section 'pairs'. i.e. One on each plug on one side of the motor. The "other" wire in each pair needs to be connected to an installed plug to insure grounding. The ignition fires three times per rotation, not six. The "other" plug of each pair fires on a cylinder that is not being sent fuel, and is just 'wasted'.
- Observe the plugs for spark with each module installed properly while someone else cranks it breifly. My guess is that they won't fire the plugs in the same order.

Easier choice (but cost is involved) is to get a Casper's Electronics igntion tester. It can do this same thing without having to be connected the car, only its battery. It has gaps in the unit that display the sparks as they occur. I have traced down issues in cars (usually a dead pair) using this many times.

I don't recall any module having the module-to-coil wires colored in a different order than the GM unit, but it may occur.