If you get the Hydro Pedals, there are support pins which help when lining up the master cylinder. When this is all lined up, it pretty much bolts together.
If you don't get the hydro pedals, lining up the master cylinder can be difficult. My friend and I did this on his '72 (obviously different pedal racks). The master was off ~1/2 inch side to side. We had to make a "spacer" on the pedal rack. It was also off up and down and forward and backward ~1/2" we ended up welding a "tab" onto his pedal to bring the mount backward more into the cab, drill a NEW hole as well as a little higher. This STILL isn't quite right. There is some binding within the Master Clutch. I am worried this binding will lead to a pre-mature failure on the master Cyl.
Lining this all up is critical to easy clutch operation.
We both have CFII clutch kits. He has an 11" disc on a 402. I have the 12" disc on my 383.
Mine is quite a bit easier to use than his.
Check out my pics below.
Good luck.