Hi guys, I changed my headgasket out about 1000 miles ago so I went out today to change the oil, retorque the head bolts, and adjust the valves. Before doing this, I had been having problems with the idle 'surging' at idle. I checked through my coolant and that was not the case, and I did some searching to find that it may be because my idle was set too high, which may have been causing my problem. Anyways, now that I adjusted my valves (which were a ways out of adjustment) the truck is surging again, but when the rpms drop (after the surge), the truck acts like it is going to die. It stumbles and acts as if the rpm were more like 400, but the truck is actually at 1000 rpm. It shakes real bad and almost dies as it slowly starts its surge again. Does this sound like I messed something up on the valve adjustment? or did adjusting the valves correctly cause something else to go out of whack, like perhaps the timing? I drove the truck around the block and under load it actually felt like it drove better than I ever remember it. Queit and seemingly better power. Any ideas? Before the problem got worse I was just going to mess with the idle stop screw a little to see if it would fix the surge, but now I think there is something more seriously wrong. Thanks for any help,

Dan