I went a different route with my Harken furler set-up. I could never get the luff of the jib tight enough so the boat wouldn't point worth a crap, and I got fed-up with the head of the jib wrapping around the forestay, so I removed the forestay. The Harken has a SWL of I believe 2,500Lbs, so it's stronger than the 1/8" forestay. As shown in the photo, the Johnson Quick Lever attaches to the stem fitting and the bottom of the furling drum. The top of the furling drum attaches to the luff wire at the tack. I removed the tang on the top swivel and it simply attaches to the luff wire at the head, and to a lanyard I fabricated to make up the difference to the masthead. For UV protection I hoist a zippered sock so I don't have to ruin my jib's performance with the heavy UV shield on the foot and the leech. So much easier and so easy to furl the jib now, and the boat points GREAT again, and no math required!
Don
The Johnson Quick Lever makes easy rigging and once the lever is pulled, the luff wire nice and tight and the boat can point again
The zippered jib sock is hoisted by the jib halyard. The jib isn't robbed of light air performance with the heavy UV shield, and best of all, being lighter, rigging is about as simple as it is with just a forestay.
Nice to be able to point again! Photo taken on Northern Lake Michigan during the C-22 Great Lakes Cruise.