The military introduced the 24 volt system to have the ability to operate vehicles in adverse weather conditions, and for standardization.
In addition, the add on equipment like radios (especially the early units) require more capacity. For a normal driver, a 12 volt system is fine. Unless you are trying to restore a military vehicle to original configuration there is no advantage. The 24 volt charging system components are expensive to rebuild.
Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine