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TracTuff RBB/ RBC Rear Wheel Drive K Swap Remote Filler Neck


Normally, the water neck on a K is pretty much right in front of the radiator and the two points are pretty much equal in height... and even then, the K is notorious for being a real bitch to bleed!

Rotate the motor 90°, tuck the back of the cylinder head into the firewall or under a cowl, and you no longer have access to the highest point in the cooling system. As a result, a huge air pock is created by the outlet tube diving under the intake manifold. This variant was originally designed for a K24A swapped RX8 and the filler tube wraps around the intake manifold and turns upward over the runners, significantly reducing the headache of adding fluid and bleeding the system at its highest point. 

NOTE: Made to Order - Contact for ETA If you have selected "Other" for intake manifold, please send an email with your order number and manifold type. If you are interested in a specific design that varies from this, please email us at 

The cap bung has a 1/16" NPT port for connection to an overflow and uses early model Honda radiator caps; such as an 88'-91' Civic/ CRX or 90'-93' Integra. The sensor port selection is optional, if you don't have/ need a sensor, don't select it. 

The billet flange requires at least 1-5/8" (total flange width 1.562") worth of space between the cylinder head and the firewall. The flange is machined with a 1/2" NPT heater port and the hardware kit includes a 90° hose fitting, a 1/2" NPT plug, four stainless M8 socket head bolts, and either a Genuine Honda gasket or a pair of o-rings. The filler tube is welded so that it sits level when bolted to an engine leaned back 15° (OEM position).