W114 Intake/Exhaust Manifold Torque Spec?

[lowellchu9]

I have a 1972 250 (W114), and I had just completed the R&R of the combination intake/exhaust manifold gasket.

Today, I started the car, but the it's still leaking at the gasket. Initially, I had torqued the nuts to 15 ft-lbs. I think this is a little light, so does anyone know what the torque spec should be?

I have the Chilton's and CD for this car, but none of these resources state the advised torque spec. Please help!

[mbdoc]

With self-locking nuts & 10mm studs, 25-30 ftlbs of torque would be closer to spec.