K-TUNED K20 UPPER COOLANT HOUSING (W/ BUILT IN FILLER & FITTING)We've taken input from guys running big turbo setups on this one. The integrated filler now clears up more room for big turbo setups. The filler neck comes off the top of the housingand can be used to relocate the radiator cap to a higher point on the engine itself. The new location is the highest point of the cooling system and allows air pockets to easily escape during the coolant bleeding process. The Filler Neck is also available with standard 1.