I don't think quality control is the problem, it's the idea that a few variants can be as close to the original mixture requirements as the many, many OEM carburetors. L6 engines of the same size will not require the same carb except by accident.
They may have developed the throttle disc size, venturi, jetting, vacuum setting, pump discharge, idle and transition hole sizes and locations, etc. on a specific engine, and will give good results... on that engine.
As your engine begins to differ from their model (displacement, CR, port size, cam timing, spark advance curve, valve area, overlap, rod ratio) the results will be worse - but perhaps tolerable.
Now, the 235 is an excellent model for this due to long use with very similar tune-up specs, so we certainly would like to hear results.
TIA
