Just one governing body at each weight and only TEN weight divisions. There was NEVER just eight traditional divisions. It started with TWO and grew from there. Now we have bigger guys in some countries and much smaller from others. Start completely afresh with something like the following weights (I'm sure there could be much improvement to those listed below).

Heavyweight - 100+kgs (220lbs+)
Cruiserweight - 100kgs (220lbs)
Lightheavy - 90kgs (198lbs)
Middleweight - 83kgs (182.6lbs)
Welterweight - 75kgs (158.4lbs)
Lightweight - 68kgs (149.6lbs)
Featherweight - 62kgs (136.4lbs)
Bantamweight - 57kgs (127.6lbs)
Flyweight - 53 kgs (116.6lbs)
Strawweight - 50kgs- (110lbs-)

Ten champs is easier for Joe Public to grasp.

Also promote more regional/world cup of boxing. Have the following Championships.

A - North American (USA, Canada, Caribbean)
B - Central American (Mexico to Panama)
C - South America
D - Asia & Oceania
E - Europe

Then have the Champions of each weights fight each other in a continual round robin. Within these groups have more sub categories so there is more talent constantly pushing forward.