lows (3b) will be fine. The Leupold rings, which are slightly lower will also work.
Why Ruger ships 5b's with their rifles is beyond me. The real mystery is why when you find actual ruger rings in the gun shops, they're 5b's also, then they'll proceed to tell you that they don't often stock ruger rings because they don't sell!?!?!?!?!?!
I'll get off my butt in a minute and get a picture of a 33mm/3b's on a RSI
Todd