Header install tips and tricks?

That's great ! Lucky you were able to drill it out Headers are a pain on lots of cars , 69 -70 big block Mustangs and Shelbys were no picnic , neither were early Camaros and birds , lots of cursing , crow bars and base ball bats ! An engine hoist helps a lot , one tool I never forget when it's header time
. All the work will pay off when you're cruising down the street with that ear to ear smile ! Enjoy the ride