Make sure you have a second set of hands. I put some gt40p heads on my car that had been to a machine shop, but, sat around for about a year. So I wound up using the compress the cylinder method. Worked great but it was helpful to have two people for holding things in place. Make sure you have an automotive pick to help the those pesky keepers. It took me and a friend about 6 hours to do all 16 with fighting around longtubes on the drivers side and beer swilling.