 The remainder were then serviced and rearmed with 75 mm guns and components whenever these became available, composing a large part of Israeli tank forces for the next eight years.The 75 mm-armed Shermans were replaced by M4A1 (76 mm) Shermans imported from France before the 1956 Suez Crisis, after it was realised that their armor penetration was insufficient for combat against newer tanks such as the IDF Centurions as well as the T-34-85s being delivered to Egyptian forces.During further upgrades, the French military helped develop a conversion kit to upgrade about 300 Shermans to the long high-velocity 75 mm gun CN 75-50 used in the AMX-13.