Originally posted by DennyW
A quick check is easy. You need someone to sit in the truck, hold the brake of course, and you take a long screw driver, put the handle to your ear, and the blade over the top of the rocker location on each cylinder, have him, or her put a load on the engine in gear, and you listen until you hear which one it is.
Denny, I like your idea with the long screwdriver, but I personally like to use a piece of wooden broomstick handle or wooden dowel rod. JMHO.