Mazda B-4000 4.0
 

I was talking to a mechanic today about timing chains on the Ford 4.0 engine. He said he recommends a re-built engine when you need to replace the timing chains because of the amount of work & a better warranty.....any thoughts out there would be welcome

Talk to a different mechanic. He sounds biased against fords. What mileage is on the engine?

it only has 90k on it. It does blow to have to remove the engine for a timing chain, but I cant believe it would be the way to go cost wise!

A timing chain shouldn't be bad after 90k miles, its the timing belt that need to be changed more often. You should get a lot more miles before needing it if you've been taking care of your truck.