Thanks for the replies. I went with the screw in clips. Got them from RT Specialities in Falls PA (about 30 miles from me). There are 12 on the front and 18 on the back. The spacing works out to about a clip every 7 inch. I marked the center line and put clips 3.5" on each side, then picked up my 7" spacing till I came to a corner where I moved the clips a little closer. I had 2 original studs on each front windshield post and used them to determine how far down from the roof to drill the holes. Did this today I'll know how well it turns out once the glass is in and I install the moldings.