Chirco Performance offers these air cooled Sand Rail and Dune Buggy single and dual relief valve plunger kits, the single relief piston and spring were commonly used on early vintage and classic Volkswagens with a single relief engine, Volkswagen came out with the dual relief in 1971, this dual relief was an upgrade to the air cooled Volkswagen beetle engines oiling system, we also offer the oil relief piston plugs as well as custom adjustable oil pressure regulator plugs, that are commonly used on high performance air cooled Volkswagen Sand Rail and Dune Buggy engines
They have always had exactly what I have needed from my 1965 Baja, to my 1974 super, always willing to give advice, the staff knows their stuff, and they have a large stockpile of parts, the only place I get my VW parts.
Regardless of whatever else I've had for cars I've always had at least one VW. Reliable and easy to work on. Chirco is without question the best place around Tucson to get quality VW parts and service.