1963 390 intake milling

[CaddyShackPA]

Working on a '63 390 with chronic exhaust leaks at the intake manifold. Measuring the loose intake with straight edge and feeler gauges, the exhaust mating surface is .012 high on the driver side and about .008 high on the passenger side compared to the intake port sections. I presume some of that is pulled down by the bolts (?), but how much is prudent to remove from the intakes on these engines? We don't want to create other problems by resurfacing too heavily.

Thanks very much for your insight!

[Dave Shepherd]

I assume you have laid the manifold on the engine, no gaskets and performed this measurement? If so I can't see how this would be an issue if the proper gasket is used, if you mill the manifold to fit flush to the head you may misalign the bolt holes, of course they can be bored out slightly to restore the alignment.