Wish this was an invite to a halloween party, but sadly it's referring to a strange low tone howl which develops between 40 - 55 mph. However when I let in the clutch and gas, there isn't any howl but a very slight vibration (from the front end) is just barely noticeable. It doesn't effect the steering in any way
I should mention that Pearl is a 51 chevrolet 1/2 T which has undergone extensive work on the undercarriage, including brakes / ball joints / drag link / all bushings etc.
What I am thinking is that it might be front wheel bearings, which weren't replaced, but were repacked. I've had the truck running for (the first time in 18 years) about a month since restoration. I haven't looked into the tranny yet or the rear end for fluid levels, but they might be next.