EF identification number

[Unfalconbelievable]

its probly posted here sumwhere but i dont have time 2 look sorry, does anyone know the cast numbers to identify the EF OHC engine quickly? And just how good is the bottom end in them?

 

[Unfalconbelievable]

Surely someone here knows the numbers, i cant find anything on it, bulding a second engine to handle more boost and heard the bottom end is tougher in the ef series? I have access to several rebuilders but i dont know what they're out of, could do with some help identifying the good engine