lifters knockin...
option 1) "cold adjustment" Most non-modified engines can be adjusted while the engine is off. To do this you simply remove the valve covers, this will expose the lifters. Now, rotate the engine to TDC. Knowing the firing order of your engine, you will adjust those lifters which are in the relaxed position (ie on the flat side of the cam). To do this, you need to look up the adjustment spec for your engine (it will be around a few hundredths of an inch). Pick out a matching gap tool and place it between the valve and the lifter. Tighten down the lifter while moving the gap tool back and forth. Continue to tighten until you can "feel" the drag on the gap tool. This valve is now correctly set. You will need to rotate the engine to get each of the valves in the relaxed position to make the adjustment (however you can usually set a few at a time).
Option 2) "hot adjustment" This method is very messy and is more common among high performance engines. Take off one valve cover and start the truck. Get ready to watch oil squirt everywhere. As the engine is running (things will be moving so watch out!) loosen one of the lifters. When you start to hear a loud clicking sound stop. Now start to tighten the lifter. When the clicking stops, take note of your wrench position. Now this part varies on engines. Usually you will now tighten the lifter another 1/4-1/2 a turn. Repeat for each lifter, and then begin to clean up. You can get fast enough to keep from having a huge mess, at one time I could adjust my entire big-block in about a 30 seconds per side. Oh and don't rev the engine with the valve cover off, this will make a big mess even bigger.
Good luck. However, go out and get yourself a manual before you attempt this. That way you get the specific info on your engine and a step by step procedure. This was only to give you a general idea of how valve adjustments are done.


