Edelbrock part #71403 Pro-Flo XT LS2 EFI intake manifold is engineered with a large plenum and tapered runners to deliver maximum horsepower and broad torque band throughout the rpm range (1500-7000 rpm). Features include a 90mm throttle bore opening and 2.75″ port exit height. This manifold produced 30 more horsepower over a stock LS6 manifold at 6500 rpm. Accepts GM OEM 90mm or Edelbrock #3869 throttle bodies. Compatible with LS1 Fuel Rail Kit #3629 (sold separately). This manifold offers a durable black power coated finish for long lasting protection and a distinctive look.