I know its a common belief that the VIN derivative stamp was omitted on some engines BUT this was an important item that the factory was responsible for doing. It was federally mandated by law. The VIN derivative was stamped on the engines prior to be installed in the cars and while it was being dressed out with carb, started, wires etc. If you cannot find the VIN on the engine, you need to assume the original block was replaced or it had machine shop work done to it. As was many hi-perf engines, owners were never satisfied and wanted more from them. Very few owners of these cars just used them for work, they abused them and many visited the dealer for warranty repairs etc.
I owned a new 1970 Chevelle SS 454 LS5 (136370K192352 date shipped. 4/19/70) and it was riddled with problems, used a lot of oil, crab problems, trany problems, front suspension problems and bad paint. I traded it off in 1972 for that reason as well as the poor gas mileage and high insurance rates.
