The 13' 7/8 DC is a good rod and I don't think that you will need to cut the long scandi for that rod. Here are the line recommendations from Mike Kinney as to how he sets up that rod, notice that he shows grain weight and head length for the the Scandi:
Rod: TF 7/8 130 4 DC 450-700 gr.
Usage: (7/8 Wt. 4 pc. 13') Standard Puget Sound summer and winter wet and dry flies.
Lines: Skagit: 500/550 with tips to 200 grains
Rio Skagit 500/550, Airflo Skagit 7/8
Short Belly Spey with tips:
Airflo Delta Spey 7/8
Mid Length Spey with tips:
Airflo 7/8 Delta Long , Rio Power Spey 7/8, CND GP 7/8 or 8/9 for deep loading
450 to 500 grains <> Head length 32 to 34 feet
This rod will cast a wide range of lines and head lengths. As always it comes down to personal preference along with your casting style and ability. I know that for some people cutting a line or head is uncomfortable but making adjustments by cutting can be a good thing. I find that most lines out of the box that are in the grain rating window for the rod will work and that cutting is not needed. When I first got started over 20 years ago it was common to cut and splice to get the performance that we were after. Today we have so many choices that I don't do much cutting and splicing.