90's Durango - Mechanic told friend to scrap

its a 4.7 , it will cost $$$ to repair if chains went, not worth fixing that engine, I put a 4.7 in my kids 05 Dakota used engine had 80k on it and still paid 1600 for it. sold the truck a few months later and got 2200.
I wouldn't buy anything with a 3.7 4.7 in it bad design on engine oiling.