67000 miles, runs great but a lot of noise from rear tires .

You mean that merely changing the two rear tires to a Michelin Tire rated for low noise could eliminate the problem? Same tires are on front and rear, little noise from front tires.

Rotate them and see if it helps... Possible cupped or 'scalloped' tread on rear tires!.. Should be able to run hand over tread and feel that... See it quite often!.. The Michelin's are worth the extra money!!!!