Detroit diesel 8v92

I often wonder myself which route i will take if and or when it comes time to rebuild. Buying a low hour motor like someone else already mentioned is a nice idea, however i dont know how to get an entire engine in and out of my sport fish without stripping the motor down to the block. Heads, turbos, coolers etc all have to come off to remove the motor without cutting up the boat. At that point you will have extensive labor taking it apart and putting it back together, which begs the question, why not just rebuild your existing motor in place? I agree though, the major cost with these detroits will be the labor.