How much break-in oil do you use? 1 qt of engine break-in oil to 5 qt of regular 10w-30 or 6 qts of break-in oil only?

If you use regular oil and it's the recommended weight for the motor you don't need any "break in" oil. All that is needed to break a motor in the right way is to keep the rpm's changing while driving the first 600 miles.That means shifting through the gears often and not keeping the motor rpm's in the same rpm range while driving.That allows the piston rings to seat into the cylinder walls. Synthetic oil is no good for breaking a motor in and should not be used until the oil is changed after the first 3,000 miles.

Need precise details here.

What engine are we talking about here? Last I heard, break in oil is no longer used in most modern built engines. They tell you a break in procedure for the car such as certain driving habits for first 500 miles and usually that is about it.

Break in oil was used when less precise manufacturing equipment was used to make the parts "mate" together for a more precise fit. Now some engines use laser cut to precision parts or other extremely accurate methods.

I have had a few rebuilt engines and have never used break in oil, I was told to use the same oil You plan to use and always use that oil (I like GTX)

and break in proceedure is break it in the way you are going to be driving it... if your going to be racing it then rod it hard, if you are going to drive it easily then break it in easy

By the way most V8 engines only hold 5 quarts of oil

None. Break in oil is an old wives tale.