Spark Plug for 4AGE BT 20v engine is IK20.
For further information, u may refer this website
http://www.globaldenso.com/en/products/aftermarket/plug/basic_knowledge/heatrange/index.html
MLOC bros, what do you think about the conversion? Anyone of you did this please share some info. I will either be getting Evo V lower arms or the AWD drivetrain..