[blucar]

I am afraid that I have to take exceptions to the comments about the Columbia being fragile.
In 1954 I removed the original 21 stud engine from my '36 coupe, it had a 103 K and was getting a little tired, had to do a valve job on it so it would start on cold winter mornings.
I replaced the engine with a well built 58AB engine with a dual Offie Super manifold, Offie heads .060 over bore, 1/4" stroke, a Weber F.1 cam and H-C ignition. I street raced the car on a regular basis, and from time to time I would run the car at the local drag strip. I destroyed several transmissions, got so good at repairing/replacing transmissions that I would R&R a tranny in less than two hours.
I would make a guess that the quality of the Columbia shifts were in direct relationship to the quality of the engine and the available inches of vacuum it produced.