I went with TCP Performance and talked to Garth. Dont tell them you want a Radiator for an airplane. Just tell them it is a Buggy conversion, it needs to be light - aircraft grade aluminum and that your Subaru engine will rev at high speeds most of the time.
They are not cheap but they are VERY good.
Also, Ram Performance converts Subaru engines and make parts for them. They sell a radiator that is made especially for the EA-81. Check this out : http://www.ramengines.com/page16.php
Custom instrument panels are now available directly from Zenith Aircraft Company exclusively for Zenith builders and owners. Pre-cut panel, power distribution panel, Approach Fast Stack harnesses, Dynon and Garmin avionics, and more.
New Custom Upholstery Kits for your Zenith Aircraft:
Developed specifically for Zenith builders (by a builder) these videos on DVD are a great help in building your own kit plane by providing practical hands-on construction information. Visit HomebuiltHelp.com for the latest DVD titles.