The "CONV1", "CONV2", etc. are conveyor numbers. They identify the molding line the block was poured on.
The casting date, the "casting clock", the pattern number (GM1, GM3, etc.) and the conveyor number provided traceability for in-process trouble-shooting in the event casting problems were noted in the finished casting or later at the engine plant during machining.
A forum community dedicated to 1st generation Chevy Camaros owners and enthusiasts. Come join the discussion about performance, builds, restoration, modifications, classifieds, troubleshooting, reviews, and more!