Combo spacers combine the features of a 4-hole spacer and an open spacer into one unit. The top half of the spacer is 4-hole design and the bottom half is an open plenum design. The 4 hole portion of the combo design improves part throttle performance by redirecting the flow pattern created by the partially open throttle blades while the open portion increases plenum volume and moves the carburetor base away from the roof line of the intake runners for improved distribution and top end horsepower.