Alright, so I plan on finding a motor to rebuild and swap into my car, but I had a few questions.

1. When finding a motor, does it matter if the motor has a spun bearing, or is it better to find one in good running condition? I am sure it doesn't make too much of a difference, but does it really matter?

2. When rebuilding a motor with the plans of boosting it, I want to use stock crank, rods and all that, just with low comp. pistons. When breaking it in, should I just use the low comp. pistons and use the stock manifold and injectors during the break in time, and then when it's time to tune it, put the turbo setup on? Or would it be good to run the turbo setup, and just not boost it, on a base-map?

I guess that's all I have to ask for right now, and I doubt it matters, but the motor that I plan on rebuilding/boosting is a Nissan single-cam KA24E.