Valve cover gaskets - cork or rubber?

[Uncle Buck]

I installed these but both sides seem to the leaking at the back

What gives? Is cork a better way to go? Any goop needed?

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[ZR]

If those are the neoprene (or similar) with steel core, never ever had one leak. Actually assembling a small block 347 with em right now.

[Uncle Buck]

I think so yes. I snugged them up some more. Seem to be sealed now. Maybe I was just being a little light with the ratchet Usually I’m known to break stuff so trying to adopt a litter touch these days.

[Old Fart]

Usually I’m known to break stuff so trying to adopt a litter touch these days.

I know exactly what you mean!

[ZR]

Pressed steel covers or aluminum?
If alum, go round n round until you feel them settle.
If steel, suggest factory style spreader bars then tighten as above.

[LX89]

I used Ford steel core rubber bead gaskets on my 89 with stock valve covers.
They have to be over 25 years old and never leaked a drop so far.

[Uncle Buck]

Hmmm, seems I’m just special. I’ll keep an eye on them. Seemed ok after a little drive last night.

[Uncle Buck]

Pressed steel covers or aluminum?
If alum, go round n round until you feel them settle.

Aluminum

[ZR]

Snug em down round n round = no leaks.