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
Hai there..pls help me with this question, i've bought a 2nd hand R34, and yes the mileage is more than 120,000km, do you suggest for me to do port polish to the engine? and one more thing, i've bought a 2nd HKS...