I plan to remove the lower intake of my Lumina 3.1L V6 engine, and seal the ridges between the two cylinder heads to stop oil/coolant leakages.

I'd like to know which is better sealing material, RTV silicon gasket sealant or cork-type sheet do-it-yourself gasket available at stores such as AutoZone?

If cork-type sheet is better, can I layer them to make the thickness of gap between lower intake ridge and engine block? Thank you for your replies!!

Asked by for the 1995 Chevrolet Lumina
Best bet is to go to dealer and get what they use. If OEM uses sealant at ends , be patient and let it cure a few hours before running. Patience and clean oil-free surfaces are best.
Thank "Ziptie12"! Just a quick question: I've heard often about some chemical liquid/solution once added to the engine's oil, will stop oil leakage from old gasket or seal, such as Bar's engine oil stop leak and so on.
My gaskets and RTV sealants are new from the rebuilt engine; Will this product help to stop
the oil leak from the ridges' bad RTV seals? at least temporarily till I have times to remove the lower intake and put new OEM RTV on! Also will this stop leak product be harmful to new gaskets and RTV seals in the long run, if left in the engine? Thank you for your responses.
I wouldn't recommend any additives , IF you are able to , I would just wait and do it ONCE correctly.