I braved the cold today and installed the new fine-tune system for the main sheet. I found that the bottom of the Harken 2618 Carbo block had a larger diameter pin than the hole at the top of the Harken 170 Hexacat. I drilled out the rivets on the top of the Hexacat so I could remove the top plate and drill the hole so it would accept the pin from the 2618. I used #10 stainless screws with locknuts to reassemble the block. This isn't the way I wanted to approach it, but I already spent the money for the blocks. Next project is to redo the traveler. Here are some pictures of the installation.
[This message has been edited by Rhapsody #348 (edited 01-23-2008).]