Thanks Sky, you saved me from having to lay the SMAK down. If Galifrey you were indeed the GOD you think you are, then you would have noticed that Chris is in Cyprus. This suggests to me that his ambient temps are 100'F + and Nicosia being quite elavated would suggest a low barometric pressure. So put the god damn shim in and run it with a P3 plug. There will be no air leak and it will just need a minor twiddle of the needles.