Mark,
The trucks weight was easy, from when I used to haul LTL freight in a straight axle.
The engine... figured it couldn't be too much more than the truck, otherwise, Clayton would've hauled by semi. So, just rounded the number up to #20,000.
Clayton, if the engine would've been on a semi trailer... I'd never have come close. Lol
Take care
See you on The Hill.!!