So after much pondering I finally ordered a Hayward and Scott cat back, it arrived yesterday and I chucked it on this morning ,fit and finish seems good, went on with no problems (apart from removal of old dummy tips which were a bit of trouble) Took it for a little run and I’m pleased with results, it sits at 70 nice and quiet still no noticeable drone but give it the beans and it sounds Much better, still no amg But so much more like it should of been all along.