[Greg Reimer 7376]

Seems to me a 62-64 327 300 used the same 2 1/2' exhaust head pipe as the 409 340,380 and 409 horse engine. I didn't consider that because,like you said, discarding the stock exhaust for a pair of headers negated any differences in the OEM exhausts. The NHRA factored horsepower was 250 horse for the 62-64 327/250, and 265 for the 62-65 327 300 horse engine. Someone should give it a try! Imagine a 327 265 in a Nova.Might be fun, especially with a 3 speed automatic.Interestingly enough,the 65 250 horse had either a WCFB or a 4 jet with 461 heads. Horsepower rating was the same as the earlier engine with the 520's.