YES.
I saw it a lot while swapping intakes with used gaskets for testing. The best idle ironically would be cold (even with choke off). After the engine warmed up, the constraints of the block, iron exhaust, and alum intake often led to small leaks and a rough idle when warmed up.
I think U need a new gasket and a perfectly flat seal then it's ok.
And, replace the locator pins on each end with real studs or bolts, that helps too.
