If I were to change a vehicle's engine, would it expand it's lifespan?

Normally vehicles last about 150,000 miles, would replacing the engine with another similar engine help expand it's lifespan, IE make it last longer than 150,000 miles?
Update: My assumption of 150,000 miles was meant for an older vehicle, one from the 1970s. A modern car could last over 300,000 miles.
14 answers 14