This variant was a limited edition release. The arcade board includes the original and Black Label games, which can be selected during boot time. The Black Label game can be identified by the black title screen.
Changes in Black Label include:
Instead of losing existing lives when entering 2nd loop, they are now preserved.
Player can select 1 Loop Mode or 2 Loop Mode at the beginning of the game, after a fighter is selected. In 2 Loop Mode, after completing stage 1-5, player now has the option to continue into the second loop as before, but can also continue if player loses all lives in stage 2-5. In 1 Loop Mode, player immediately fights Hibachi after defeating normal stage 1-5 boss, which can also be continued after losing all lives.
Hyper Meter is now filled properly, so it fills faster.
Boss patterns are changed in 2nd loop.
Chain meter now has 5 digits, so it no longer rolls over if it reaches 9999 hits.
As a result of allowing existing life stock to carry over to 2nd loop, Basic Rank can reach higher than in the original game.
Source: Wikipedia, "DoDonPachi Dai Ou Jou", available under the CC-BY-SA License.