I've installed a set of stainless 58/475 with billet wheel on the 475 on my 98.5. What I'm looking to hear from other people is what kind of turbo pitch u r hearing from twins. This set sounds almost the same as my stock hx35 without the ring but louder. I was expecting a more deeper whistle alittle disappointed. But the kit spools awesome and runs hard. I wouldn't change the setup because of that. Also when I take truck on interstates at 80-85 mph its sitting at 10 psi and singing pretty loud pretty annoying on a long trip. Anyone else experience this with your setups. Thx.