Towing a 68 on car dolly

Yes, new clean Mopar oil with the Chrysler additive. Doesn't smell burnt after 300 miles, but rear end is hotter than it seems it should be. Drums too. I can still touch without burning myself, so maybe it is just me in a panic. It is 95 degrees here.
I just don't like towing with dollys. I burnt the 8.25 in my 74 charger up towing it from Richmond Indiana to Columbus Indiana, it was plum full of oil too, the pinion shaft looked like it'd been hit with a blow torch. I had the driveshaft out and all. I figured it had to do with the front of the car being on the dolly and the angle causing the oil to pool away from the pinion shaft. But I've also towed cars just fine with a dolly so who knows.

Oh one last note, you probably get BETTER mileage as you have the free spinning trailer axles versus what ever gear ratio that is in the charger. Less drag.