Beat the **** out of it, or go easy for awhile? I've heard both ways, what do you guys think is the proper way to break in a new LS based motor?

 

This is what I usually do:
-10w30 regular dyno oil during break-in. NEVER use Fram. Get a NAPA Gold Filter = Wix. Good filter, good price. If you have money to burn buy a K&N = good flow and filtration.
-Do not take it over 3000 rpms for the first 100 miles.
-Do not drive at a constant rpm for too long.

1. Start it and let it idle, rev it up a little for 20 minutes. Change oil/filter.
2. Drive around the neighborhood in lots of stop and go and lots of shifting and downshifting for 20 miles. Change the oil/filter.
3. Drive it again the same way around the city for the next 100 miles. Change the oil/filter.
4. After that, I will take it up to 5000rpm but will not redline it. I drive it normal and spirited still not letting it drone on for too long at a constant rpm. Change oil/filter at 3-400 miles.
5. Dyno it/rip on it. Change oil/filter.

On the other hand it seems that the really powerful motors are built and trailored to the track and then beat on. They say you should drive it the way the motor is going to be driven to seat the rings properly.

 

http://www.mototuneusa.com/break_in_secrets.htm this should get thing going, you be the judge !!!!!!!!

 

Start the car,take it to operating temp and proceed to dyno.