If you have the intake manifold milled, be mindful that the alignment rings might need to be made "shorter" (otherwise, they might hold the manifolds out from the head, resulting in leaks).
A straight milled edge should allow modern manifold gaskets to seal the joint area. However, Cuthbert's suggestion/observation of using two sets of gaskets is a reasonable option, if the leak is small (1/16" might be too large a gap?). The original manifold gaskets were thicker than the modern gaskets (I had a NORS set for comparison). I have used exactly what Cuthbert describes and it was a satisfactory long-term solution.
