I got out and re-adjusted the valves again today. After much deliberation, and measuring, I decided to go .005/.009. I know this is WAY tight, but I figured I'd give it a shot and see how it went, at least for a little while. I put the valve cover on much looser as well.
...and.... It sounds great! I feel like I'm driving a new truck. The motor is nice and tight. There's only the slightest hint of valve clatter.
So why did I go so tight? My original 8/12 had stretched to about 10/14 in a weeks time. I figured if I wanted to end up with 7/11, 5/9 would just about get me there. I torqued the adjuster nuts to 35 ft-lb both times.
If I'm seriously endangering my motor, let me know. Otherwise, as usual, thanks for all the info. I feel much more confident wrenching on my truck after hearing everyone's input and experience, especially since I'm still a newb-mechanic.
