doing an engine replacement on a friends car. he bought a engine from japan and i noticed a few differences right off the back. the main one being the oil pan. the hump is on the front of the oil pan on the Japanese engine and on the back on the one hes got. his engine also has the vtc solenoids in the back of the heads, the other one doesnt. oil filter housing is different, throttle position sensor also looks different. some of the coolant passages in the back of the engine also. my question is, is it even a thing where you can swap a Japanese engine into a US 300zx? how can i know for sure he got the right engine? is there an engine code somewhere on the block? thanks in advance