Standard Exhaust Valve Guide. Fits Big Twin 1948-1979. Standard Outside Diameter FE-3026 When the Engine has to

When the Engine has to work against the pressure & vacuum it utilises some of the power the engine produces

* Use copper OEM exhaust gaskets

* 360 degrees of adjustability for a customized riding experience

2 x Internal Zipper Pockets for all your valuables

Standard Exhaust Valve Guide. Fits Big Twin 1948-1979. Standard Outside Diameter FE-3026 When the Engine has toCast Iron: After chemically separating several samples of cast iron material , analysis and evaluating the test data, we decided to have our own specification of cast iron made exclusively , us. We specify elements such as carbon, silicon, manganese, nickel, chromium, copper and sulfur to produce a highly pearlitic structure with dense fine grains , excellent wear resistance. * OD = 0. 5650" Std size * ID = 0. 3745" * Replaces OEM # 18138 79 Matching