Spectre Dual Plenum Kit (Fits Carburetors & TBI w/5-1/8in. Inlet)Spectre's polished cast aluminum dual plenum air intake has 4 inch inlets. It is 3. 5 inches tall and it measures 8 inches from the air cleaner stud to each inlet. It fits carburetors and TBI throttle bodies with a 5 1 8 inlet. The 4 inch dual inlets are 90 degrees apart and designed to match up to all Spectre 4 inch tubing, filters and accessories.