I don't suggest modifying an existing block system. "Upgraded" an 8:1 system to a 9:1, but the existing block hardware was not beefy enough to handle the loads, found out the hard way 3 days into Tybee.
If you added a point of purchase you decreased the load on the hardware (blocks)itself. I think you were just using some old busted-butt, brokedown, shite. i've used an 8:1 modded to 9:1 since it was allowed by class rules ,at least 4 Tybees worth.