Looked where I thought it might be, but it wasn't there... Anyone know what the torque spec is for those nuts? The crossmember to frame, that is.

 

If a specific bolt isn't listed in it's relevant section of the FSM, then look at the last page of section T. The very last entry lists the torque for the different bolt/nut sizes. The 6T and 8T listing are the bolt strength, which should be stamped on the head of the bolt.