Looks to me as if you need 3.5oz for 90 min. addition and another 3.5oz for dry hop.
I am planning on doing this recipe for my Big Brew. This will be the first SMASH.
"The ordinary world is only the foam on top of the real world." Tom Robbins (B is for Beer)
"It's a beautiful day for baseball. Let's play two." Ernie Banks