When I upgraded to the 6:1, I found that the bottom block wouldn't fit in the traveler and I had to add the shackle......Do I need to upgrade my traveler?
The older, larger Harkens have a post that's a bit too wide for the top plate of the traveller car. Either grind a flat on either side of the post (doesn't take much), or open up the "ears" on the top plate a bit with a couple of pairs of pliers.
Make it fit. You do not want a shackle on the lower end of the main sheet.
This is what comes with the boat on the top:
![[Linked Image]](http://img.alibaba.com/photo/200363102/PLATE_BOW_SHACKLE.summ.jpg)