I recently replaced the intake gaskets on my 5.7 litre v-8 in my Suburban trailer hauler and have developed a problem.  The engine runs fine and quiet until I get a mile from home and then the valves start tapping loudly as if they are getting starved of oil.  I installed the Fel Pro gaskets as per instructions with the blocker plates toward the rear of the eng.  What could have caused this? I was careful not to get any old gasket remnents in the open engine when I scraped them down.  The engine runs fine otherwise although it does idle a little faster than before the gasket job. The oil pressure guage still reads around 32 lbs.  I have around 170,000 miles on this engine.  It smokes a little but other than the leaking intake gasket didn't have any other problems.  Could it be the gaskets are incorrectly covering an oil or water passageway in the heads?  

You've got me. There are no oil passages that the intake gasket could block. Sounds like evreythings sealed up if it's idling faster now you may have had a vacuum leak before the fix. Try checking to make sure you didn't set the timing advanced to much. Distributor off a tooth? Too much timing advance and a warm engine could be ratteling your valves.  

Yeah, I was thinking the timing could be off ( I hate removing distributors with electronic ignition, you can't mark the rotor like you used to be able to in the old dist.)  It ran so sweet after I put everything back together, I didn't bother to time it.  I will dig out my timing light tomorrow and check it over and set it right and see if that works.   Thanks!  

Intake gaskets must have a leak check for that...