Break-In. How Long?

As best I can remember this, more or less, is written in a dog eared early70's era mopar performance engine bulletin.
Follow camshaft break in procedure, cool engine to dead cold.
Re-start and check timing and idle adjustments, when warmed up make 10 half throttle pulls in second gear from 1500 to 4500 rpm, coasting in gear each time. Cool to dead cold.
Re-start, make 10 full throttle pulls in second gear to 5500 RPM, cool to dead cold.
Change out break in oil.
Race!