The EC version is a 68060 without integrated FPU and without an MMU (Memory Manage Unit).

The PowerPC 603 was designed to run in low cost systems and portable machines. The first PowerPC 603 was slower than the PowerPC 601 at the same clock speed - partially due to the 16KB L1 cache as opposed to the 32KB L1 cache in the PowerPC 601. Because of its size and low power usage, it was quickly ramped up to higher clock speeds.
The PowerPC 603 was followed by the 603e, adding 16KB of L1 cache to some models, and the 603ev which shrunk the manufacturing process from .5 microns to .35 microns on some models, allowing it to be clocked even higher.
 
References:
Motorola MPC 603/603e User's Manual  Motorola MPC 603 Doc Archive