Just replaced mine with 5/16" Dyneema, from Marlow Ropes. I bought 82' and that's probably a couple feet too long. And that's after splicing in the shackle. OBTW, I have a 27 TR.
P.S. I don't like a lot of extra line laying around. The 82' gives me about 4' of tail behind the clutch with the halyard secured to the back of the boom.