I got a 1995 Chevy Suburban and between 45 and 65 mph im getting a whistling/howling noise and it kinda sounds like when you blow on top of a bottle. When im hearing the noise and switch to neutral the noise goes away so its only when im in drive. Its got new U-joints, tranny was redone, new throttle body gasket and i tried taking the front driveshaft out with no change in the sound. To me it kinda sounds like its in the middle of the truck but im running out of ideas. Any help would be appreciated.