I like to take mine and hold about 1800-2000 rpm for a minute or two. This to up up the lifters and chain tensioners with oil. Then I take it out and get it to normal running temps. Then I start putting slight loads on it taking it a little higher in rpm each time and little harder into the throttle. First time 1500-3000 let it slowly coast back down then 2000 to 3500 coast raising the rpm a little each time. I take the final one to about 5400 the last time and 3/4 pedel. Then I turn around and head back to the garage varing the rpms. I feel this helps to set the rings and wash out the assembly lube. I put a total of about of 50 miles on it and change the oil. Then I cruise it around to about 500 miles geting in it some but no long wot runs, again change the oil.
I did this to my last short block and it's almost 4 years old and has seen tons of abuse.