99 silverado misses bad

My 99 silverado 2500 6.0 started to miss. I changed the plugs and the wires to no avail. I noticed that the fuel pump is whining pretty loud. I have 74000 miles on it. the fuel pump was changed at 36000 miles a couple of years back.I changed the fuel filter also.Is there any way to check each individual coil? also is it possible that the fuel pump is acting up and is not out altogether. Please help.

Just to let anyone know. I think Ive found my problem. I went Autozone and had them put the small handheld codereader on it and it showed a misfire on cyl 7. I bought a coil there and changed it in the parking lot. It has quit the missing and I had the guy erase the code. Looks like my problem is solved.