Yep, that's why I could do it with no previous experience. You can calculate the length if you or someone you know is good at higher level math. Measure the length of the mast
to the rigging
pin centers, measure the distance of the chainplates from the center point of the mast
location at right angles, otherwise level with the base of the mast, and then calculate the length of the shrouds. Cap shrouds will be two length calculations, one is the height to the spreader the other is the side of the triangle to the masthead pin. Last, measure the height distance from the base of the mast that the chainplates etc are different and add this to the calculated length and you have the the total length of the stays and shrouds. Subtract out the length of the turnbuckles extended out to about 3/4 of their adjustable length to get the wire lenght. Did it that way on the 2nd boat I built.
Rerigged my current boat measuring the distances to the turnbuckles with a tape and/or the shroud
. A combination of halyards will hold the mast up while you do all the measuring. Once the lowers are done and fitted, the mast will stand by itself and give you enough support to go the mast head
in conjunction with the halyards.
If there is a question about length, err on the longer side. You can always cut more off and buy another cone to re-rig the terminal
I like Norseman Terminals but StaLoks basically work the same. Should be able to do a terminal in less than 10 minutes once you get the procedure down. My only experience with HiMod didn't turn out well but that could have been because of the way the owner cut the wire and tried to assemble the terminal.