As time goes on "period" as a definition can be fluid. Many mid/late 60s cars were updated under the hood but still had their looks from the early 60s. To me that's not a traditional "sin", in several venues beyond our base it's the same. Imagine a M/P Vette from 63-64, still old paint and old wheels. The racer builds a new engine in 68 with new induction and maybe adds a big (bigger?) hood scoop. What traditional show would tell that owner and car to fuck off at the gate? None I've been to. It's easy to be faithful to a proper build by doing lots of photo research. Best source? Swap meet magazines. Dig through that box and get multiple example pics, not just 1. Restoration? Completely different approach. By rights we should never mention zoomie headers from late 65, a Woody Gilmore FED from 67, the Don Long Prudhomme"Super Snake", but how many are here? Be realistic, reasonable, even a bit open-minded. More than anything, have fun. I've said it before but taking this stuff and ourselves too serious ruins the experience and it's rewards.
Larry, was the intake filled to the top of the runners back in the day. Man that's a lot of epoxy resin.