RTV is a lame option for this application.
For cylinder base gaskets we only use Curil "T". Curil "T" is a high temp non hardening sealant that is one of only a few sealants that are certified for use in nuclear reactors. This fact alone gives us extreme confidence in this product.
A thin coat on both sides of the gasket and you're good to go.
We have found that for most applications on air cooled engines RTV is lacking in anything like durability and internal beading resulting in oil worms is totally unacceptable in quality engine overhauls.
RTV works well to seal water cooled engine applications like water pump and water manifold issue.
Remember this mess still leaked. RTV is evil.
