GM crate engine break in procedure
1. Run the engine between 2,000 and 2,500 RPMs, with no-load on the engine for the first 30 minutes.
2. Drive the vehicle with varying speeds and loads on the engine for the first 30 miles. Be sure not to use a lot of throttle or high RPMs.
3. Run five or six medium-throttle accelerations to about 5,000 RPMs (55 to 60 MPH), then let off in gear and coast back down to 20 MPH.
4. Run a couple hard-throttle accelerations up to about 5000 RPMs (55 to 60 MPH), then let off in gear and coast back down to 20 MPH.
5. Change the oil and filter with 10W30SG oil and appropriate ACDelco oil filter.
6. Drive the next 500 miles normally, without high RPMs (below 5,000 RPM), hard use, or extended periods of high loading.
7. Change the oil and oil filter again.
8. Your engine is now ready for many happy cruising miles
This is just the break in procedure for GM's crate motors, however it does show that you are not supposed to just baby the engine when it's brand new.
Steve