75-80 MPH wobble sounds like balance, the wobble at slow speed should be diagnosed by an alignment Tech if it were myself! I had Sam's club rotate and balance my tires recently and they messed up my road force balance which was only 7K miles old but i took it back and did another Road Force balance (not at Sam's club) and my wobble from 50 to 70 MPH is gone! Found a shop in ABQ that does have all Hunter 811 Consoles and the
Hunter GSP9700 Wheel vibration Control System solves wheel vibration and tire pull problems that balancers and aligners can’t fix and Haweka adapters and the Tech knows how to use the equipment! Low speed wobble i do not think would be balance but mine did start small wobble but it was around 20 MPH and got really bad around 50 MPH! I would do a Road Force Balance if ya want it done correct!

LT Tires specs are around 45 to 47 but P rated limits are 25!