Dapat laging "complete" pag bili ng bagong engine para less hassle... tranny, engine, ECU, kung puwede ngang front cut ang bilhin mo mas maganda. Since you said 1.6 yan, meaning 4A-FE, salpak lang sa existing bolts ang kahit anong 4A series na pang front wheel ha.

Make sure you get a mechanic who knows what he's doing. Usually when you get an engine kahit na sabihin pang "sariwa", pabuksan mo na since nakababa naman.

Good luck...