do i really need a new one? regular maintance doesnt removed oil pump..why would i need a new one when replacing the head? sure new is better but i can get used ones for cheap

 

you need to use a GSR or Type R pump. as well as timing belt and water pump. the oil pumps from b18c1/5 have a higher flow rate which is needed to activate Vtec properly. and the hole timing belt thing is because the b18c1/5 oil pump/water pump have more teeth then b18b. weather you use a new or used one is up to you.