Originally Posted by Richiehd
Thought I read somewhere, castings were too thin to drill. Besides, early heads, no hardened seats.
Oh ok most have had the seats changed out by now. But yeah if the seats are still from 1960 then you will need to change them out as well. I bet you could get a few bucks for them on ebay since they are unmolested for 40 years. Usally they had the seats done in the 70's.
You can drill and tap the same holes as any chevy head. Most of the bolt is in the boss anyway. Really does not need to go very deep.
Most cars of that time did not have a/c in performance cars so the heads were not drilled unless you had one with the options for a/c and engine that came with humps OEM.
You can also always run the alt and power steering down low in the old school position.
hope this helps some.