If the machine shop honed the block correclty and got all the clearances correct and you have the flat tappet cam broken in now there is no reason to "break in" the motor for 500 miles Take it out and get after it right away to help seat the rings properly
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Take it out and get after it right away to help seat the rings properly 
