This is the style box that is on my car. I get the hissing also, but i don't think it's as loud as the posted video. I'm using the Chrysler style coupler that Bergmans makes so you don't have to cut the steering shaft. There's no isolation between the box, and the wheel. That's where I feel the sound comes from. I have a Borgeson box on my 65 Comet, and i get hissing from that setup also. I couldn't use an isolated coupling on that car, since there's not enough room between the box, and the firewall. I think if a rubber isolated coupling is used, it will lessen the noise. JMO.
