There are older threads here you can search for as all the different ways to do it and the different experiances people had.
I did the swap:
got a 74 454 from a 2x4 truck
got a SBC engine crossmember (3piece) from a 73+ 4x4 truck
bought ORD SBC engine mounts
bought 4core Rad and longer mounts
bought new clutch pp assy & flywheel for my SM465 & 454
converted to Hydro Clutch so I didn't have to worry about the Thorley Tri-Y heders I wanted to run
beat the drivers side firewall with a 4lb sledge..not real bad, just a bit of a dent for the valve cover.
shoehorned the 454 in there and been rockin eversence
