I did mine on my 62 Bird 390,,,the hard one to do was the one behind the motor mount,,,but after removing the mount it went pretty smooth,,,oh yeah,,,,while you have the frost plug out,,,put your finger inside the block and feel down low for crud that builds up,,,,if you have as much as i had,,you may have to poke around to loosen it all and flush it out,,or it will end up in your Radiator core.