The Edelbrock Bowtie II Victor Jr. 23 degree #2972 intake manifold provides maximum performance for engines using unported Chevrolet Bowtie cast iron heads #14011058, #14011034 and #10134392. The intake manifold port exits match up to these heads with little or no matchin g required. This is ideal for classes where rules restrict the porting of intake manifolds to match cylinder heads. The #2972 can be tuned for greater performance gains when used with 1" or 2" carb spacers.