Denny - why did GM switch from Carter to Rochester??? - GM owned Rochester!
I am unaware of any serious problems with the 1941~1948 Carter W-1's. The early ones, beginning in 1932, had some issues; but Carter continually worked on the issues. By 1941 they had a great carburetor.
The only reason I do not include the 1949 (arguably the best of the W-1's) is that most parts of the 1949 are unique (read expensive) including the accelerator pump. The 1941~1948 are both readily available, and parts are also readily available.
As to the distortion on the B's: when we were still doing these, we had no problems other than the castings were again leaking within 3~5 years. I just can't recommend something that needs major work every 3~5 years. We did find the distortion you suggested if we tried to hurry the process. Once we figured this out, we started taking out a maximum of 0.003 inch per heating. It sometimes took a week to get the castings true. Too much work for the results!!!
Jon.
