Here's the
advice I got for my new block.
(Disclaimer: All I had to break in was the piston rings, since I was using 86k miles heads. Others might want to give advice about breaking in the top end)What you want to do is heat cycle the rings. Babying the motor will NOT accomplish this. Varying the RPMs is what you are after, to heat and then cool the rings. So, no long highway trips where the RPMs stay constant. (I'm not sure what constitutes "long", but I took my brand new SVT on 300 and 400 mile drives the days after I got it - probably not the best idea.) If you are driving on the highway, every once in a while, run it in 4th for 15 - 30 seconds to heat the rings, and then let them cool by running in 5th for a while. You probably don't want to do WOT runs or beat on the engine any during break in (duh), but the rings will never break in properly if you totally baby the engine.
I'm running 1000 miles on dino oil before I complete what I consider "break in". I chose to use dino oil because I couldn't justify the extra cost of Mobil 1 for only 1000 miles, and the dino won't break down too much in that short amount of time (I'll have my 1000 done in 10 days!). After that, Mobil 1 and K&N oil filter all the way!
I think the owner's manual has a section on break in. You can also find a bunch of opinions on break in
here .
