First time around, Glen (who makes house calls) had to do the installation 3
or 4 times before it would stop leaking, and he had to use a lot of Permatex
on the gasket. I understand that strictly speaking, it shouldn't be
necessary to use any. The stock 504 valve cover hadn't been leaking.
Glen left, and in the next day or 2, I found I still had a leak, producing a
nice little waft of smoke around the edges of the hood. Glen came out again
w/a new gasket. I should also mention that (long story short) I used 4 new
spark plug tube seals, but 2 of them bought at one time and place, 2 bought
at another T&P. Glen seemed to have stopped the leak, and then a day later,
it was back! I called Glen, and he said that if he tightens the bolts any
farther, they'll strip.
I've also tossed this around w/Brian Holm, who's suggested the following
possible causes:
1) Difference between the 2 prs of spark plug tube seals. The leak was
definitely coming from around 2 of the spark plugs on Glen's 2nd visit;
where it's coming from now I don't know.
2) Warped valve cover.
3) Different spark tube length between 504 and 505 engines. Anyone know if
this is the case? I wouldn't expect it to be.
Any other thoughts? If I can get this solved, it'll make my day! Thanks!