According to Cliff Ruggles' site (https://cliffshighperformance.com/articles/quadrajet-casting-number-chart-1938), the two letter plant code indicates what factory the quadrajet was cast at. It seems reasonable to assume, that for the most part, Stage 1 carbs were cast at a single facility (LK) but may have been cast at other facilities (LA) to keep up with demand. Or maybe the bleary-eyed stamper mistook an A for a K? I look forward to hearing what you find out!
