These elbows are designed for use in high hp race applications. An internal divider optimizes flow distribution to all ports of the manifold by reducing turbulence. High Flow Elbow number 3849 is an ultra high flow version which measures 4.5in. from flange to throttle body centerline. During flow testing this elbow provided up to 1,050 cfm with a 95mm throttle body. Does not accept LS1 throttle bodies. Intake Elbow number 3814 has a universal bolt pattern and is the best way to adapt a single throttle body to a Dominator 4500 style flange EFI manifold without sacrificing air flow. The throttle body flange accepts 90-95mm LS1, LS2 and Ford 5.0L based throttle bodies.