Thanks Pontiac Jim and Goat Roper. So now Im thinking since I have the intake manifold off, maybe I should pull the valley pan and get a look at the cam and lifters.....Thoughts or hints?
You could check out the lifter wear if flat tappets. Clean real good around the valley pan first before removing to keep any dirt or debris from falling into the engine. Get a new valley pan gasket set & new PCV valve rubber grommet while you're at it as well.. Undo the 2 valley pan bolts and remove.
Pull your valve covers. Then rotate the engine to get both valves closed and on the base circle of the cam lobe. Back off the rocker arm adjusting nut enough to free the rocker arm from the pushrod. Remove the pushrod remembering which end goes under the rocker and which end goes in the lifter cup - don't mix them up. Then you should be able to slide the lifter up and out of its bore and inspect the bottom of the lifter for wear or cupping. Use a straight edge over the bottom of the lifter to determine the wear IF it is not visibly worn/cupped.
Then re-assemble in the reverse order making sure you put a little oil back on the lifter base so it is not dry when you fire it back up. Rocker arm nut gets torqued to 20 ft lbs if stock. If you have poly-locks, mark the ploy-lock and count the turns out to get it off, then write it down. When you re-install, put the same number of turns back on it to get close to where it should be, then do a final adjustment with engine running to get your "zero lash." Then do the other rocker the same way and inspect. You can do this procedure for each cylinder & pair of lifters if you choose to or just jump around and check a few.
When done, install your valley pan seal/valley pan and the two bolts. Do not over toghten the 2 bolts or you will crush/distort the valley pan. I like to use a little sealer along with the cork gasket to ensure it does not leak. Many like the RTV stuff which is good, but I like a product called "Indian Shellac" which gets applied with the brush applicator found inside the bottle. You just brush it on. Put some on both surfaces and make sure you get a nice layer in the corners where the gaskets meet. This stuff is like glue when it dries. Next favorite is the "Yellow" 3M Weather Strip & Gasket Adhesive. I believe it also comes in black, but seems the yellow is more common and what I have used.
Trim any excess valley cover gasket that may stick out along the intake side of the heads to ensure a good fit on your intake gaskets.
I think that cover it?
If you have not already done so, clean-up near the distributor to get the casting build date of your block. Easier to get at it now than later.