I have to wonder if the "restrictions" were done as part of reducing NVH (noise, vibration, harshness). The small snorkel opening would act as a venturi to speed up the air flow and maybe that was a requirement for the resonator boxes (think: blowing across the neck of a Coke bottle). I had a new model '94 S10 with the TBI 4.3L. Thing had an intake snorkel opening *smaller* than the air box opening on my DR350 dirt bike. Along with the tiny opening were a couple of resonating chambers molded into the snorkel. It was a CAI though ...