I haven't seen too many posts in the archives nor any listed here on having to rebuild the bottom end of the M103 at a certain high mileage reading nor even to change the piston rings. I have read of some burning oil, which is probably caused by the rings, but nothing siginificant to require a rebuild or a new crate motor.

So, at what point do the shops typically see these engines in for rebuild? Probably later than sooner, but what mileage is typical? I gotta know, b/c I have read some of these crate motors are about $5K....help.