My '73 C30, '74 K1500, '76 K20, and '84 C20 were all non-catalyst, non-EGR engines due to the GVW per year. The chart would spec restrictors based on the type of vehicle/duty and whether it was a 2 bbl or 4 bbl. My point being that if Waveski's intake and carburetor are too hot, the restrictors should help reduce the amount of exhaust cross-over heat being absorbed by the manifold.

1957 Chevrolet 5700 LCF 283 SM420 2 speed rear, 1955 IH 300U T/A, 1978 Corvette 350 auto, 1978 Yamaha DT175, 1999 Harley Davidson Softail Fat Boy