Finally got my 83.5 running. Long embarrassing story which I will
relate later.

In the process I came across a mystery connector hanging freely behind
the engine, It is a T2 (two prong connector, female) with white and
yellow wires going to it. This branches off the harness on the section
that goes to the idle and  full throttle switches.  Engine runs fine
with it disconnected.

  Any insight?

Please reply directly as I am on digest.
Cheers