UNFORTUNATELY I had to replace the intake gasket on my 83 H/O due to coolant leak. But I am so glad I removed the intake. I found this in #8 intake port. Then i figured out what it was and where it came from. This car has 23000 miles on it, I'm the second owner. The first was a friend of mine. Intake has never been off. Wonder how long it's been sitting on the valve???? Wonder if it has damaged the valve. I never would have found this if it wasn't for the coolant leak. But then again, maybe I would have........