I would say since since I have done the job removing the intake manifold is the best way. I broke two sets of 1/4" swivels trying to do it. Also it is difficult to thread them back in and since the head is aluminum you run a big chance of cross threading them. With the manifold off the GP's are even easier to replace than on a OM 617. The manifold is easy to remove and replace. You do need to use swivels for the manifold bolts though.
