Progress on my 340 Hood Scoops!

Just curious as to where you heard to drill the holes 4inches. I have found two different articles in Mopar magazines. One says the holes should be
4-1/4 inches, and the other seems to indicate that it should be 4-1/8in. I'm not trying to say yours are wrong, I just want to be sure before I buy the wholesaw. I know 1/4 or 1/8 wont make much difference at all appearance wise, but I want to be sure the seals/inserts fit properly.

(note - as I was typing this I was also surfing ebay and noticed a set of seals on there. It says "When these rings are inserted into the standard 4 1/8 inch hood scoop opening hole, the smaller end fits through the hole and with a hard pull, it snaps right into place leaving a clean raised edge top and bottom." So, I'm even more confused now.)

Also, what did you use to attatch the scoops to the hood? I have been told the factory used sort of a speed nut on them. I saw a set on ebay but they were $60 and came with the studs which I don't need. I was thinking about using regular nuts and washers, definatly cheaper if they will do the job.