I hadn't looked at the Roush website in a while, but found it interesting that they're not selling the 402 anymore, but they offer 5 flavors of the 427 SB. Isn't that the motor that was giving them fits for a while?
All of their small block 427's list 10/30 as the recommended
oil. I want to say that they used to recommend 10/40 for the 402.
I'm using my own home brew method, with a 50/50 blend of Joe Gibbs 15/50 and 10/30.