[TimG427]

ItBites, you are up to speed on your big block Chevy stuff....I still love the 427 Chevy engine, the 454 hit when emissions came on strong and aside from the LS6 (454/450 horse) the 454 was a low compression, medium performance engine, even in the 1970 Corvette, it only generated 390 horse and the '71 LS6 version only had 425 horse with 9.1 to 1 compression.
There was a truck 427 block that does not have "HI PERF" cast on it and it has a different deck hight.