"Throw the gasket in the trash, run a 1/8" bead of right stuff around the perimeter on the block and set the valley cover on. Put you bolts in finger tight and let set for 30 minutes then torque to factory spec."

I agree. The trouble with the torque spec is most likely having to remove the intake to get at the cap screws. 

It sounds to me that either the cover is not torqued correctly (cap screws backing out - no thread locker) or for some reason the cover is not laying down correctly (component(s) interference). 

The below is sourced from BLUE THUNDER -

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Cork gaskets have always been a joke really. Throw the gasket in the trash, run a 1/8" bead of right stuff around the perimeter on the block and set the valley cover on. Put you bolts in finger tight and let set for 30 minutes then torque to factory spec.

I know we've gotten off track from your original post; hopefully nobody minds. What carburetor and headers are you using? Header primary diameter & exhaust diameter? Is that an ECZ-B intake or painted Blue Thunder? 

Built for street not strip. I love this setup, its snappy off the line, 0-80 in short order, 20 in vacuum, idles very smooth at 800 rpm and sounds great.



.150 Stroked Y-Block:327.25 ci @ >1hp per ci
 

Brent, it's not likely that you're tightening the cast valley cover to the point of deformation, but the same can't be said for the gasket.

Thanks for sharing the engine specs. It looks like you have an Isky E4 cam with 111 LSA, instead of the off-the-shelf 108. Considering you have 327 cu. in., do you now wish that you had selected a larger cam? 

Here is a previous discussion on proper fit -

https://www.fordbarn.com/forum/showthread.php?t=217874

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I mentioned the Mummert valley cover to inform that it is a quality cast aluminum cover, hoping to hear you can’t overtighten because it will not deform under pressure. I will keep an eye on the gasket as Ted mentioned. The leak is lessening as I tighten an eighth of a turn after a run.



.150 Stroked Y-Block:327.25 ci @ >1hp per ci
 

I don't think it is the valley cover.  I have the M8ummert cover on both of my YBlocks and do not have any leakage.  I always use some RTV as Ted mentioned.


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

How about more photos and engine specs for your Bird?

The valley cover, like valve covers, is easily over-tightened. I would not trust most ft lb torque wrenches to be accurate to 2-2.5 ft lbs; use an inch-pounds torque wrench and tighten to 24-30 inch-pounds.