Towing with a pintle hitch

Might be best to go scale your truck and trailer,see how much weight you can carry.
I've hauled paving machines with a trailer on a pintle hook,single axle dump,but it didn't weigh as much as a dump truck.

 

That’s a high percentage of weight on non drive axles so it’s probably not a great idea in snow or ice conditions but on dry roads it should be fine just don’t get the trailer tires in a soft spot. Not quite sure I understand how you will get 40k though
10-12 for the trailer and 20-25 for the truck????
As far as if the pintle is stong enough the ring on that trailer should be rated for anything that trailer can handle without being over gross
The hook on the truck could be a problem
In my opinion it needs to be one with 6 3/4 or 5/8 bolts not one of those dinky 4 1/2 inch bolt ones for a light/medium duty truck
As far as the breaking strength of one of the heavier ones they will hold everything a d8k will pull it good ground conditions…..which is a lot probably 75k or more drawbar pull

 

Just shy of 38,000 lb excavator, but I don’t use a single screw….