MISERABLE Mileage.............

linc's advice is very sound and complete.

One other thing I would check is the heat riser in the exhaust manifold. Not too big a deal during the summer. But very important in the colder/winter months.

With those long intake runners, the /6 has a habit of condensing fuel into liquid in the intake if it isn't kept nice and warm. The liquid fuel will pool and run into the cylinders making the car run crappy, and affecting fuel mileage.

Be sure and do your valve adjustment when the engine is thoroughly heated up. I did mine just the other day with the engine running and fully warm. It definitely made a difference.

Please let us know how you fare!

Chris E.