Exhaust manifold gasket help please.

When everything is machined dead flat from the factory it would only make sense to not use gaskets.....but everyone knows that cast iron ages and with years of heat cycles the cast iron is no longer dead flat unless you get the manifold mating surface re-machined as many folks do. So, if your manifolds are still "dead flat" (machinist term) then you should be OK, if not I would use gaskets. I've always used gaskets myself because it doesn't make things any worse but it can seal up some warpage caused by all the decades of heat cycles. treblig