Supertech,  This is a brand name that is highly respected when it comes to the Sports Compact Racer, Rams Have been using Supertech for many years now and have worked with them to develop Valves for other applications, So if you Are After a Good Quality Set of Valves or Valve Spring Kits then Supertech May have what you are looking for as they Have one of the most extensive range of performance Valve Train Products available,  for Manufacture’s such as Audi, BMW, Ferrari, Ford, GM, Honda, Hyundai, Lancia, Mazda, Mazda, Mini, Mitsubishi, Nissan, Opel, Peugeot, Renault, Subaru, Toyota & Volkswagen.

They have there valves in some of the worlds fastest Toyota 2JZGTE,  Nissan RB26 and many many more.

for some of the most popular engines they make components for scroll down.