Wilson Manifolds open spacers have become the standard in NASCAR NEXTEL Cup racing, but are for use in any application where a top quality light-weight billet spacer is desired. Open spacers increase plenum volume and move the throttle blades away from the roof of the runners, allowing the air/fuel mixture to turn more easily into the runners for improved distribution and mixture quality. Open spacers will add mid range and top end hp. Wilson Manifolds is the only manufacturer to produce open spacers in thicknesses from 1" to 2" in 1/8" increments for 4150 carburetors for precise tuning and for applications where hood clearance is at a premium. The engine builder spacer kit includes all nine open spacers (4150) in 1/8" increments and is a must have for any dyno room and for track tuning. * Adds mid & top end power * Increase plenum volume * Allows the air/fuel mixture to turn more easily into the runners by moving the carburetor up away from the runner roofline * Improved distribution and mixture quality * Will add mid range and top end hp * 1" to 2" Heights in 1/8" increments for 4150 carburetors * Wilson Manifolds is the only manufacturer that offers multiple heights for 4500 carburetors * 4150 spacers are designed to pass NASCAR No-Go Gauges
