Man John , I know that that tether (frayed out all ta heck from the ends of the splice) looks super sketchy at best, but I'm here ta tell ya right now that John Carpentino out of Nazereth, PA spliced that bad boy, and the dude means business. It's my belief that a small chip truck couldn't bust that thing, but... maybe the test isn't worth it; not to mention that (but I'm sure you already know this) it's really a moot point since the life support is really all about the prussic cord, and so... just a word, or seven hundred about that...
I (who weigh a buck fifty dripping wet) always had the best luck with the black Beeline, which, if you can believe this, holds about eight grand. I would just wrap it four times in a counter-clockwise direction around the climbing line, and then attach the loose end back to the carabiner rather than trying to run a proper VT. Let me back up... What you have there is (to the best of my knowledge, is: (1. A black beeline good for eight grand or thereabouts. 2. A tanish-colored beeline good for, I wanna say 6.5 grand or somewhere therein. 3) A longer and suppler RIT cord, which a guy wants to say is good for dang close to seven grand or at least in the ballpark. 4) The pulley. 5) The biner.
So what ya do (but perhaps you know all this stuff, and I am redundantly boring you) is: 1) Clip the biner to the proper attachment point on yer saddle. 2) slip one end of the black Beeline onto the biner. 3) Put (only one end!) of the zk1 tether onto the biner, and attach the head of the wrench (by way of removing the slick-pin) to the suspended climb line). Physicall (with your left thumb) "bend" the attacked wrench down (toward the earth) so that you will have enough room for step number six, but first comes step four. 4) Open up the pulley, place it on the suspended rope in mid air and then place both "wings" (for I have no better word) of the pulley onto the biner. 5) Place the other end of John Carpentino's tether on the biner. (In this way both "wings" of the pulley should be snugly sandwiched between either end of the prussic chord once step six has been completed which is this: 6) Wrap the remaining loose end of the black beeline in an upward direction four times in a counter-clockwise direction, and then attach it to the biner. 7) Let's call it "Lucky Seven": make sure that the clocking gate of the biner is properly locked, and yer ready to rock.
Sit yerself firmly down into yer saddle and see if the whole (One is doing all of this on flat ground, I hope!) contraption will firmly take your weight without slipping on the single line. If she slips, then yer gonna need more wraps and a different prussic cord since the black beeline is gonna be too short to afford any more; but, I gotta feelin she wont slip, so do this: stand yerself up on the ground again with your leg muscles thus producing slack in the system, and try taking up the slack via grasping the wrope with your right hand upside down on the climb line below the pulley and pulling up. Clear as mud?? If the whole contraption slips up easily, then you know you're golden. She's gonna work a charm. If she slips when ya sit down on er, yer gonna need the longer bee line (tan colored), or, failing that, even the RIT cord, and a guy can fiddle around with a proper Valdotain Tress if he wants, but I just recommend straight up counter clockwise turns up the rope since, when weighted, it darn near forms a VT of it's own accord (let the reader understand) anyways.
Failing all of this, just go ahead and order Kevin's Rope Runner Pro... pretty sweet little piece of riggin. But I got a soft place in my heart for the ZK1... dang fun to climb on imho.
Man!!!..... So sorry If I gave you a huge headache with all of this ramble, Ixkllr.