The K&N E-3770 is a round, 14-inch outside diameter by 6-inch tall replacement element with a 12-inch inside diameter and an inner wire support. K&N's washable, reusable High-Flow filters use layered, oiled cotton media designed to improve airflow and capture contaminants. Because the element is washable, it can replace a disposable paper element over the life of the vehicle, and the manufacturer says each filter is backed by K&N's No-Hassle Lifetime Limited Warranty. The manufacturer also states that the filter only needs cleaning every 50,000 miles under normal highway driving conditions, which makes it a practical long-term cost compared with repeated paper replacements. Keywords: K&N E-3770 cotton gauze air filter, 14 inch round washable air filter, 6 inch tall high-flow element, reusable performance air filter.
Fitment is the key buying question. The manufacturer presents this element as a drop-in for the factory air box, but its 14-inch diameter means it is most often used in custom 14-inch air cleaner assemblies. The manufacturer's racing listings show E-3770 as the 6-inch element in its Fourteen Inch Drop Base Air Filters - Chrome line, with a raised element 9/16" above carburetor flange on the chrome base. The manufacturer's notes on assembly height also state that Total Height = minimum clearance required above carburetor flange. Confirm your intake, airbox, or hood clearance before ordering.
DIY installation is straightforward for a drop-in element: remove the old filter, check the sealing surface, and seat the new one according to the original installation instructions. The element arrives pre-oiled, and the manufacturer lists a re-oiling amount of 3.5 oz (103 ml) for cleaning intervals. Keywords: 14 inch carburetor air cleaner element, 4-barrel air filter element, K&N 14x12x6 replacement, washable cotton air filter clean and re-oil.
The manufacturer states that this filter only needs cleaning every 50,000 miles under normal highway driving conditions. Dusty or dirt-road driving calls for more frequent inspection.
The manufacturer states that the filter will not void the vehicle warranty and is emissions legal in all 50 states.
The manufacturer states this element is pre-oiled and designed to drop into an existing air box or assembly, so no special tools are required for the filter itself. Measure the clearance above the carburetor flange or intake before ordering, because the 6-inch height and 14-inch diameter can conflict with hood height or nearby components. For cleaning, the manufacturer's general instructions call for removing the filter, tapping off loose debris, applying the cleaner specified for oiled cotton filters, soaking, rinsing from the clean side outward, and drying before re-oiling and reinstalling. Confirm the exact cleaner and oil kit with the manufacturer before use.
