Our billet -16an thermostat housings feature a manually machined base flange that allows for the oem thermostat and O-ring to fit seamlessly into the 1.8t block.
Cast aluminum conversion features -16an male fitting welded onto an ecs thermostat housing
Both items are built on a per order basis please allow a 2-3 week lead time
Please reach out to us via email if the option you're looking for isn't listed, or if you have any questions regarding the product. We will get back to you as soon as possible.