The Edelbrock 3847 Elbow can be used in square bore (4150 style) manifold applications. It can be mounted forward, backward, or sideways on our Victor EFI square bore (4150) style manifolds, when fuel rail or waterneck clearance permits. Because of its low profile, it will not fit Chevy manifolds in the forward mount configuration as it will hit the water neck. It accommodates LS1 80 mm or Edelbrock PN 3864 LS2 (90mm 4-bolt) or Ford style 75mm throttle bodies. The 3847 adaptor features: 1) Bolt pattern fits LS1, LS2 and Ford 5.0l based throttle bodies. 2) Adapts to standard (4150 style) square bore manifolds.3) Fits manifold either in a forwards, backward, or sideways configuration (user determines clearance). 4) The throttle bore center sits 9.00" forward and only .56" up from the manifold 4150 flange. The throttle body flange points down on a 12 Deg angle.5) Internal divider optimizes flow quantity and distribution into the manifold.6) The PN 3848 Low Profile elbow will also be available. It's throttle body bore is 7.00" forward and 2.00" above the manifold flange.