The rectangular port intake with rectangular port gaskets works fine on the oval port heads. Looks great too. We had an 8-1 smogger 454 with the rectangular port intake, 750 Holley, a mild cam and headers running mid 13s on no traction street tires. Pretty cheap performance.
Not really necessary.
The Square port intake on oval port heads was used by S/S cars for years to get better performance.
Was NHRA legal too.
Works just fine with the ports as is ,just use the square port gasket and not the oval port gasket.
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