RE: 20V head on MC block

[James Desveaux <desveaux@ucla.edu>]

Peter:

I wouldn't read much into part number similarities, one way or the other.
One thing you should keep in mind, though: The 20v turbo heads, and the
later MC heads had sodium filled exhaust valves.  My understanding is that
the regular 20v head has regular (non-sodium) exhaust valves.  Depending on
what you are application will be, and whether you intend to convert an NA
20 valve head to a turbo, this is something you ought to keep in mind.

- Jim