what year big block is the best for swap?

[trkklr77]

anything after 73 will be a 215hp 454, stock. may have 049 large port ovals but more than likely be a peanut small port head. especialy a 86.
open chamber heads
2 bolt main

anything before WILL have
large oval port heads
be a minimum of 270hp ,ls3 396/402
open or closed chamber heads[closed chambers are better for power.]
2 or 4 bolt main.


i have a 78 454 with a huge cam and 049 heads and it easily made 300hp