I'm looking for the stiffest to see if there is something bigger than I already have. As can be seen from the first three posts, I'm already at the top of what I understand to be available. It's a turner 6 pack (HT) and I've just tried a 800 lbs spring with is about right but I didn't haver all my kit on. Just wondered if there might be an 850 or the like out there that I didn't know about. However, I think will anything over 800 the issue is the free length. I'm not sure it's possible to make a spring of that weight with a 2" compression and a free length under 130mm.
As for changing the bike, no thanks, I'm quite happy with the 6 pack once I et this sorted. And yes, I've already had it pushed for my weight. (220-210 depending on kit and how much water)