Jim, I have a 1989 H30G. I want to bring a couple of more lines from the mast base back to the cockpit. I need two more of the special turning blocks that attach to the mast base. These screw into thin nuts that slide into a groove under the mast base. They are described as "single blk. w/spring" on drawing number H30A2620 (Mast Step Detail) in my owners manual. Is there a standard part number from Harken, Schaefer, etc., that I can order from my local chandlery? Or, can you tell me where I can obtain these blocks? Thanks.