Chrysler Repair: 2004 dodge ram with 2002 motor: no spark, dodge ram 1500, 4 digit numbers

Question
 I changed out my motor 2004 dodge ram 1500 with a 2002 motor. Both 4.7  Now i have no spark at plug.Both motors ran when i pulled them. Is it possible for the crankshaft tone wheel different and if it is can i flash the pcm with the 2002 vin number or swap the pcm so i wont have to pull that motor again

Answer
Hi Johnny,
I don't have manuals for the larger engines of the truck line, so am only able to respond in general to your situation.
I suspect it doesn't have to with the pcm or the vin or the year of the engine, but rather something specific to do with the spark generation system: cam/crank sensor signals not being present, wiring from sensors to the pcm, ASD not being closed so that voltage is not being provided to the coils, wiring from the pcm to the primary coil windings so as to "drive" the spark, etc.
Why not try for a fault code readout via the ignition switch:"on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time? Then watch to see if the odometer window changes from mileage to show instead any 4-digit numbers preceded by a P. If so, let me know what they are and we can go from there. Otherwise, ask Kevin what he thinks when he becomes available later in the day.
Roland