I towed a 3-axle backhoe trailer from California to Tennessee in 1980 with a 70 Fleetwood, with a 472. Gross weight on the car and trailer was 16,700 pounds, by the truck scales at the Arizona point of entry, where I had to get an over-wide permit. I was moving back home to Nashville, with everything we owned on the trailer, and crammed into my 59 Burb with my wife behind the wheel. 2,500 miles at 5 MPG, (10 on the Burb) but no problems out of either vehicle! Those 472's are tough!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!