I agree with the others on that the big deal isnt the piston rings sealing up anymore they will be fine if had a good torque plate hone job. However I would recommend doing things alittle differently if you are using a flat tappet cam. Todays oils arent really adequate for flat tappet cams. since the automakers have gone to roller cams and such plus the epa has cracked down on the amount of zinc oil makers can put in conventional oils its a struggle to get these cams broke in correctly, getting the lifters to rotate quickly is of utmost importance or you will roll a lobe and be buying another cam quicker than a cat can lick his ass.
I would recommend using Rottela t, and adding a can of stp oil treatment they both have high levels of zinc and other anti wear additives. Make sure your cooling system is full, (no air pockets) so you wont have to worry about shutting the engine off for running hot in the first five minutes. I like to take off thermastat housing and fill from there untill full, then install housing and upper hose and fill radiator that way most air is out of motor. Start the motor and run it at between 1500 and 2000 for 20 minutes varying the rpm to properly break in cam
Heres a link that's a good read on the best oils to use and breaking in a flat tappet cam. Goodluck, Charles
http://data.melling.com/Tech%20pdfs/...Rev4-12-07.pdf