No MSD no problem! Just to see if I could do it for a friend, I put an Ebay intake and a Holley 650 carb on the mule 5.3 and fired it up on the engine stand with the $40 Ebay harness and the factory PCM.
I made a tune with a linear timing table based on RPM like a conventional distributor engine would have and turned off everything not needed. All timing adder tables were turned off and timing retard tables were turned off other than the knock sensors. This is like having a mechanical advance only distributor with no vacuum advance.
A few have mentioned that it would be better with a MAP sensor, and they are right, it would be better on the street with the MAP sensor installed and the timing table set to adjust for manifold pressure as factory (this would be like adding vacuum advance). I have never done this before so it was an experiment, and once in a vehicle I will install a MAP sensor and make adjustments to the timing tables to take advantage of the MAP sensor.
The only connectors hooked up right now on the Ebay harness were the two grounds, cam sensor, crank sensor, coolant temp sensor, knock sensors, coil packs, the two 12v power feed wires, and the 12v key on/crank ignition relay feed wire. Knock sensors are not needed but I left them for now.
The tune actually worked but of course may need final tweaking once in the car. The engine seemed to like it, too bad it still has no oil pressure!