2005 Chevrolet Silverado 1500HD 6.0 motor. I am getting a misfire code on ignition coil "D". Which coil pak is coil "D"?

p0306 refers to cylinder 6 misfire detected===causes engine mechanical fault--wiring---ignition/fuel system--injector ---ECT/MAF sensor---ECM
IF there was a mechanical fault (hydraulic follower ) or valve it would be there most of the time and not just on start up. Possible injector fault but I would be inclined to check out the MAF sensor codes p0351 &2 refer to ignition coil A and ignition coil B primary /secondary--circuit malfunction === causes --wiring--ignition coil--ECM ( all causes for the both)
going on this check out the coils and check that the wiring and connections are clean and tight. basically I would be inclined to change out the coils and check /replace the MAF sensor.
change the engine --sounds like advice to get some extra money out of you.

Possible Causes:

• * Air leak in the intake manifold, or in the EGR or PCM system
• * Base engine mechanical problem that affects only Cylinder 6
• * Fuel delivery component problem that affects only Cylinder 6 (i.e., a contaminated, dirty or sticking fuel injector)
• * Ignition system problem (coil, plug) that affects only Cylinder 6

It sounds crazy but it worked great for me put the key in the ignition and tap it LIGHTLY with a hammer. I did that key turned and hasn't stuck since.

does the engine run rough when this happens the light could be a misfire most auto parts stores will scan it for free a p0301 is cylinder one misfire and p0308 is cylinder number 8

Misfire is usually a plug or wire gone bad. Check your plugs and wires and replace any fouled plugs or damaged wires and that should resolve the issue. If it doesn't then you will have to look at the Coil pack and Crank Position sensor.

misfires can be caused by faulty ignition components, but they can also stem from other components. Such as faulty injectors, or improperly timed or unseated valves. Sounds like you have touched on all of your ignition suspects.
Are there any codes present other than P0304, P0305 and P0306? If so they should help guide you in the right direction. If not, You might want to make sure your valves are seating and if so, go ahead and swap an injector from a misfiring hole with a good one from a hole with no misfire. (like switch #2 and #4 injectors for example) if the misfire moves to cyl 2, you know the injector is at fault.

DTC Number
P0160 DTC Name O2 Sensor Circuit No Activity Detected Bank 2 Sensor DTC Number P0300 DTC Name Random/Multiple Cylinder Misfire Detected

177 ft lbs

First check fuses, then test blower motor, Last Temp control switch