[cnavarro]

You won't have any problem with breaking-in the reconditioned cylinders if you do the prescribed cam break-in process. I've never heard anyone recommend letting the engine idle for the first 15 minutes. Yes, cam break-in is important, but as soon as you get that done, you want to get a good load on the motor to get the rings to seat up and you don't want an overly rich condition or no load that would lead to glazing over of the cylinders/rings resulting in poor ring seal. Your best window to break in the rings properly is in the first 45 minutes.

Good results with seating of the rings also relies heavily in how well everything is cleaned and prepped - I recommend after a precursury cleaning, that denatured alcohol and chemwipes are used to wipe down the bores until the chemwipes come out as clean as they went in. You'd be suprised what will come off of what is considered a 'clean' cylinder with the above process. The nikasil dust/honing oil mix is very pervasive and is some very nasty stuff. Then a good oiling of the bores and rings will ensure you don't have excess scuffing and streaking of the bores that can occur with rings and nikasil.