[Mr70]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> I have another auto L78 block with a 138 vin from the same plant with a T1027 date which would have been Nov car which also lines up.</div></div>
Recheck that.
138 series were station wagons or Monte Carlos,and weren't eligible for the #854 L-78 4-bolt main solid lifter engine.

Oshawa Ontario didn't produce any 1970 L-78 Chevelles or Elcos,so exclude them.
Flint Michigan didn't produce anything during Oct.Nov.Dec.'69.
..and Sept.'69 was an extremely lean month for Flint.I've yet to see/hear of any 1970 L-78's from there so far,so you might be able exclude them too.
That leaves 4 assembly plants for the 1970 L-78 Chevelle/Elco,and nearly 99% of production were manual trans. equipped.