Thanks for all the replies, as usual all good advice for determining what the problem could be. You all put me on the right track for looking at the problem logically. Ends up it was the throw-out bearing. The stock one was too long, I got the short one and I am back in business. Although I feel a bit dumb not diagnosing this problem properly myself, I did make some improvements (e.g., re-curved the Hurst shifter), during the multiple removals and installs of the transmission. Also, I am a lot better at transmission installs now. Thanks again,
don