Originally Posted by WeeAsp
My knee jerk reaction is that your symptoms are created by the tires.
The more aggressive the tread pattern, the louder the tire.
Further, you've lengthened the suspension geometry. So, the chance of any sort of "harmonic" noise translating into vibration is also increased.
He said the noise stopped when he removed the drive shaft, and since the tires were still rolling when he test drove this possibility, I'd rule them out.
Sounds to me like the front joints do not like that angle. How many miles are on them (front joints)? Have them replaced and re-install the drive shaft. Have a shop balance that front shaft as well.