Do the motors only last around 175k Miles?

Hey XB people. I dont own one but do alot of side work on the mechanical side. I have had two of these come in for motor swaps in the past month im finishing the second now. with a lift its a pretty straightforward job. But anyway both were within 10k miles of one another. One send a rod through the block the other was making the noise getting ready to. Whats the mileage someone can expect on these (assuming oil changes on time and checking oil between changes).

Also if you have any questions about the motor swaps on how I do them let me know. Within 3-4 hours the motor is on the ground. Well subframe is anyway with the trans.