1996 dodge ram 1500-vibration problem

I just purchased this truck and it has been in the shop since. There is a lot of vibration at a low idle and the shop can't seem to figure it out. Im not sure what they have tried, no one is telling me anything. Any ideas out there. any help would be apreciated.
A friend of my says it might be the valves because they said you can hear them, maybe bad rockers?

Might be something as simple as a loose motor mount, or mounts...

Might be something as simple as a loose motor mount, or mounts...


I just took the truck to another shop for a second opinion, and they found out that in that dodge v6 motor the firing order was change to make the truck have more horsepower but in the end result you have a vibration only at a low idle. They said that it is very comon in all dodge trucks/cars with the v6 motor.

Does this sound right?