Take a piece of cardboard, push the studs of the spoiler through so you cam mate the cardboard flush to the base of the spoiler, then trim it to match the contour of the shape of the spoiler.

Then take the carboard patern, and position it on the deck lid with about 1/4" forward of the rear edge of the deck lid (or where you feel it will look the best, just not right at the trailing edge, it will almost hang over then!)

Then transfer the holes from the template to the deck lid, and double check the under side where you'll have to notch out the holes larger for the speed nuts etc... and to make sure as Dave said... you won't run into the seal or anything else! (oh and make sure it's a 69 spoiler that goes all the way to the body edge at the top of the 1/4 panels... had a friend who was sent a 68 spoler for his 69, and it's about 3/4" shorter on each side) Doh!

Good luck!

Brett - 67 Drop Top 455!