I have searched the forum and couldn't find any write up on this. I have some new valve springs coming and would like to read up on it before i start tackling this. Any input would be great. thanks.
Comp 910's I'd imagine.
You need a special tool to compress the springs, a flathead screwdriver, a 10mil, 11mil and a 13mil to get the IC piping out of the way and the valve covers off.
Once you get all that out of the way, take the 10mil (deepwell) socket and remove the glowplug from the first cylinder you intend to work on. Stick a coat hanger in the hole, and have a buddy rotate the engine by hand off the harmonic damper bolt (15/16ths? been a while) until the coat hanger rises up as far as it'll go.
Remove the rocker arms from the cylinder you're working on, 10mil I believe. Compress the spring with your chosen tool. The "keepers" are two pieces that fall into a recessed area in the face of the large washer looking piece over the valve spring, and pinch the valve stem. Compress the springs very slowly so you can make a positive hands on removal of the keepers. They're easy to drop and very small and hard to find again.
Remove the old spring, reinstall the new spring, and keepers. The keepers have a ridge machined to the inner "half moon" and the valve stem has a groove. Make double and triple sure the ridge is securely inside the grove when you back the spring compressing tool off. Other wise the first time you fire up the truck it'll throw the keepers and drop the valve in the cylinder. Major overhaul time... Reinstall the rocker arms, taking care to make sure the pushrods are still seated on the lifters, and line up with the rocker arm properly. Gently but firmly tap the valve end of the rocker arm with a rubber or plastic mallet. If the keepers aren't seated properly tapping the arm and slightly bouncing the spring should kick the keepers out of the recessed area.
Take a good look and make sure everything looks just like the cylinder next to it.
Reinstall glow plug.
Repeat 7 more times.