So after talking with people in the know and given everything I have tried and eliminated so far. I am now being told its likely pushrods and hydraulic lifters worn with clearance issues or clogged oil passages not getting oil to these same parts which would of course also cause wear and clearance issues. I am being told this is a very common issue with this motor and it does not really affect driveability other than the noise and I could probably put another 100,000 miles on the motor with no further issues. However if I want to fix it the repair is not extremely difficult I just remove the valve cover, inspect everything, replace any loose hydraulic lifters and pushrods, remove any sludge and clean oil passage ways etc.. No special tools needed and nothing too technical other than tightening the three bolts that hold the lifter system in place to the specified torque. So any guidance and experience anyone can give me would be greatly appreciated. Also if you are one of those guys that enjoys looking up parts and cross referencing part numbers I would appreciate you confirming the hydraulic lifter/lash adjusters part numbers and the pushrod part numbers from someplace like http://www.rockauto.com/catalog/catalog.php or whomever your favorite parts supplier might be.
Thanks