Hi, The 'scution advance pipe' is aka the distibutor vacuum advance tube. runs from the rear carb around the back of the head to the distributor. The 'clip' they are referring to is just a support of the pipe and (this is where I am a bit fuzzy) but I think it fits under one of the rear cylinder head nuts. At any rate it isn't too critical where you support the tube unless you are going for concours.
And, I apologize if you've heard this before but, do make sure you install the oil feed pipe banjo bolt into the rocker pedestal and into the rocker shaft before you tighten down the rocker shaft. If you try to install this banjo bolt after you have tightened the rocker it is very easy to strip the threads from the aluminm pedistal trying to get the hole in the shaft lined up.
good luck,
Dave Phillips