Is there any reason why I cant use a cardboard gasket in plce of metal

[Rusty_S85]

The pie plates worked fine, as would aluminum foil if the head and cylinder were filed and sanded flat. The indian head shellac is old school stuff that works well on cast iron engines. I had a few catastrophic failures with it on aluminum head engines before I gave up on it. Teflon tape rope is the answer for flawless thin headgaskets. Read up in the archives from a guy named Headsmess.

Really? We use it as a sealant for header gaskets on aluminum heads all the time without a problem. The only problem we have is that copper exhaust coat spray some times it works some times it burns through.