Ok how's this ask the guy doing the install what break in he prefers.
I did 3 heat cycles the installer did 2 before I picked it up and then I did 200 miles of everyday driving......... Then I drove it like I stole it and haven't looked back.
BTW about 15-30 min of driving is enough and about twice as long to cool then repeat.
i plan on asking the guy, but wanted to get as many opinions as i could to see if there's a general consensus. everyone has their own way, just wanted to see what everyone else recommends. thanks for all the replies.
My 4.10s were installed yesterday and I did three or four heat cycles. The worst thing you could do is go fast right out of the shop. Just run them to operating temps and let them cool down and repeat 2 more times. It's not necessary, but you should do it especially going to the track the same day. At the factory, ford just runs them on the dyno and parks them. The 4.10s make the car rip!
Our shop recommends a 500 break in as well, with a 2-3 heat/cool cycles. Of course, I also have personally just jumped in and drove. But the break in is more geared (no pun intended) for heavy trucks, and rigs that haul trailers. We had a customer burn up a brand new set of Dana 80 gears in 150 miles because right after he left the shop he loaded up a 30ft travel trailer and hit the freeway.
Also, I do recommend that you change the gear oil after 500 or so, because brand new gears do have a coating on them that will contaminate the oil.