i would like to thanks for all the great help ahead of time I have a 71 demon putting a big block in I have a 71 383 hp motor and a 77 440 the 383 has a mild build already so here is the question because this 440 was smog motor do I stick the money in the 440 punch it out 30 with a nice street cam and alum heads or can I get good power out of the 383 doing some research the newer casting blocks are stronger and cool better i know any big block a body car can get up and move just wanted to see some of you opinons thanks