Pat
I don’t know where to get the boots for the 70. Maybe a GM dealer. If you do find them the holes need to be 2 ½” in the body and 2” in the doors. The location (center) is marked by divits in the metal. The best way to cut the holes is to use knock out punches, a tool used to cut holes in electrical enclosures. You will get a cleaner hole than with hole saws. When I cut them on my ElCamino I had the fenders off. It will be hard to do without removing the fenders or the doors. The knock out set should be available at a good tool rental.
I don’t know where to get the boots for the 70. Maybe a GM dealer. If you do find them the holes need to be 2 ½” in the body and 2” in the doors. The location (center) is marked by divits in the metal. The best way to cut the holes is to use knock out punches, a tool used to cut holes in electrical enclosures. You will get a cleaner hole than with hole saws. When I cut them on my ElCamino I had the fenders off. It will be hard to do without removing the fenders or the doors. The knock out set should be available at a good tool rental.
