Offenhauser part # 6274 is a Chevy 396-454 Dual Quad Hi-Rise Manifold. We recommend AFB carbs for all Dual Quad manifolds to preclude possible carb clearance problems. When using Holley carbs, it may be necessary to mount them sideways or move them forward and rear. See adapters # 5832 and # 5880. These carb adapters do not solve the clearance problem in every case. Be sure to measure for clearance.
NOTE- Dual Quadrajet manifolds do not have enough area for 2 Holley spread-bores. Use Carter, early Rochester, or Holley Model 4360.
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