Bob J.

You are correct.  I did not support the "tail pipes" Nor did I connect the
two pipes together.  They are supported by the bolt flanges from the
cylinder(s) and the sliding crossover connection, thus they can expand and
contract and have only one place where they are solidly attached ( the
cylinder).  No evidence of cracking yet after 180 hours.

Bob Smiley
N94RJ