If those are a 1 piece header, then on an a body anyway, here's what has to be undone...both motor mounts, starter, drag link, oil filter adapter, rad hoses, coolant, remove distributor so when you jack up the motor it won't hit the firewall. Don't fight it, just pull the parts. Make sure you have the adapter gaskets first. Now some A body hooker 1 3/4 super comps are two piece, and I could drop those will a lot less fuss. And definitely high enough in the air so that you have room to manuever the header from the bottom. Mine always went in from the bottom - the only way from the top was while installing the engine.