[Chip327]

If you can pick up a Haynes Repair Manual. Its not as descriptive with some things as Chilton is but man it is a great book for all the smaller stuff including setting valves. Did my first motor rebuild just from following instructions in the Haynes Manual.

I adjust mine with truck off - same thing not as messy

Here what I follow:

1. Bring number one piston to top dead centre
2. Tighten rocker arm nuts (number one cylinder only) until all play is removed at the pushrods. Rotate between fingers until slight drag is felt ( or until doesnt fell like it is moving up and down at all anymore )
3. Tighten each nut an additional 3/4 turn to centre the lifters.
4. Adjustment for #1 is now complete , continue with each cylinder ( top dead centre ) until complete.
5. If in doubt , definitly go less than more , like said earlier dont over tighten.

I dont know , this works for me and truck runs like a dream for a long time now