These are the "cargo hold" values for all faction's trucks, as well as most other vehicles (such as quadbikes):
transportMaxBackpacks = 0;
transportMaxMagazines = 50;
transportMaxWeapons = 10;
These are the values for the Ifrit and the Hunter:
transportMaxBackpacks = 5;
transportMaxMagazines = 90;
transportMaxWeapons = 10;
Strider is identical apart from only taking 2 backpacks max.