I didn't do custom length, but I did get rid of the cables and connectors I didn't need. So instead of having four molex and sata connectors on one cable I just put on what I needed and moved the position of the connectors around.
Thanks. I did shorten the tubing but it fits in the R4 with the stock length.
They didn't come off clean, left a lot of residue. I used rubbing alcohol to get it off.