Stainless Steel Recess in Firewalls for Filters/Governers
If you are installing a constant speed prop and your engine has an accessory case mounted governor (most do), you will need to put a recess in the firewall (except RV-8/8A). Necessary for most spin-on oil filters too. We suggest doing it during initial construction. These kits provide the stainless steel material and instructions for the job.