I have an A frame for lifting my mast and I just used the blocks from the main sheet. I have a new mainsheet system but the blocks I used were I think the original ones used by Parker on my 275. They have red pulley wheels. I used them to make 4:1 system using an old halyard off a 36ft boat, worked fine. I used a turning block at the mast step to take the rope to the coachroof winches.