These are the seals you have heard about, that can eliminate intake leaks, now at an affordable price,  PEEK (polyetheretherketone) is a linear aromatic semi-crystalline thermoplastic developed in the late 1960’s. It is widely regarded as the highest performance material capable of being processed on conventional thermoplastic equipment. PEEK  has a melting point of 650°F (343°C) with a continuous use temperature of 500°F. It has outstanding creep resistance for an engineering thermoplastic material and can sustain large stresses over a useful service life without significant time induced extrusion.
SOLD AS SET OF 2
H-D 3,     1-45/64” ID
Fits The Following Harley-Davidson Models
1940-1947 Knucklehead 
1948-1954 Panhead