Some of the photos in the thread show the old o-rings looking pretty ordinary, so I'll hold on.
I've got a few other things that aren't quite ready for the new core - want to install an EGT probe in the manifold while the turbo is off, but I haven't quite finished the EGT code for my data logger yet, so want to get that done - not necessary but nice.
Plus I'm still messing around with the WGM and it's nice to have the same baseline setup while I'm doing that.
The comment about performance was a bit tongue in cheek.

