As mentioned on the title, I would like to know what are the differences that can be easily differentiated between the two engines if possible. The main reason as to why I asked this is that I'm planning to buy an engine for my Evo 7 but a friend of mine told me to be aware that the seller may sell an Evo 4 engine instead. Therefore, I'm a little worried about this and would like to get this sorted out...

 

The first visible thing is the cam cover, E7 has evolution text on the cover, E4 text Doch 16 valve.
Thermostat housing and waterinlet is completely different, turbo etc