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? 

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
 

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? 

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.

"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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