Eric,

Make sure you measure the valve clearance before you loosen any of the valve nuts. Last time I did a valve adjust job on my '79 300SD, none of the valves need adjustment after 25,000 miles since last time that were adjusted. That made the job a lot easier.

I suggest you get .003, .005, .013 and .015 inch feeler gages and use them as go, nogo gages to measure first and maybe you won't need any wrenches.

P E H