The "standard" Volvo's green book torque specification is 37 lb-ft.

However, I use poly bushings, and because its stiffness is greater than the standard rubber bushings, I suspected that the Volvo torque-based spec wasn't appropriate. I found another specification elsewhere that simply described tightening until the largest (mid-point) curve of the side of the bushing swelled to the same diameter as the metal cups above and below it, so that seemed applicable to poly bushings, and that's what I use.