The floor has been radiused for better fuel distribution and the manifold is machined for a thermostat provision to make using on the street no problem. Rear of the manifold has a spring loaded backfire valve assm. and rear of intake is machined 1/8" pipe so boost pressure can be picked up.
Ports are rectangular, measure 2.375" x 1.625" with room left to enlarge buy the buyer if they choose to match the ports to different cylinder head applications. Manifold from deck surface to blower surface measures 4.375" tall.
Manifold is tapped in the rear 1/2" pipe for water temperature gauges.
This manifold fits all 9.80" deck engine blocks 396, 402, 427, 454 and most other aftermarket Chevy blocks.