In particular the O.S. LA engines use a gasket that is .005 thick. So is packing tape. I cleaned the mating surface of the crankcase and stuck a piece of tape on it. Then I cut the center hole with a new Exacto blade and opened the bolt holes with a hot piece of sharpened rod. A little trimming on the outer perimeter and I have a new gasket.

Hope the heat of the engine doesn't shrink it.

I do the same thing with aluminum duct tape.   Works fine for head gaskets and header pipes too.  Just re-tighten a bit after the first run while still warm to squeeze the tape gum down a bit more.

Dave