alright, I have a 95 1500 4wd it does the shaking thing, also. I was thinking, could it be the driveshaft?
the deal with sandman's truck is the throttle position sensor located right next to the throttle body. my truck does the same thing. it also surges when I am on the highway I find the I can get around the annoying problem by being choppy on the gas to downshift and stay there whan going up a hill. otherwise, it will shift in and out of overdrive everywhere. turn the overdrive off, and it does it in the other gears. the position sensor is about 40$ not too bad.