We just finished a 10 day excursion from Ventura Ca to Yosemite towing a 3000lb Glastron Carlson boat.
You have to have LOTS of patience in our old babys. 18mph comfortably cruisen over Grapevine, both ways. Ran same temp at noon and midnight.
Oh i have a 69 21 foot travco that just clicked 60k on this trip. It is a bone stock 318 "semihemi".
It ran like a top the wholetime. Guess im posring outta pride for her. ( we call her bubbles)