Fuzzy

I have a 1998 silverado ext cab 4WD, 5.7L V8. Bought it recently with 144000 miles on it. I am experiencing the death wobble, and replaced all the shocks, as they were ridiculous worn out. I have the shop manual coming in the mail, so for now am working with the Haynes manual. Anyhow, from what I've been able to look up, it sounds like the 4WD should have a steering damper. Mine does not have one. I've been all over the steering/suspension area, and determined my pitman arm and idler need replaced, tie rods are suspect, and also determined without question there is no steering damper installed. My question is should a 4WD have a steering damper factory installed? Oh, took this to Firestone the day I brought it home. Got their 25 dollar inspection. Told me shocks were bad and I had some bulbs out. What can you expect for 25 bucks? Never do it again. I'll save the 25 bucks and put it towards the idler arm.