Thanks for posting your timings for these clocks mate, I will give this a go later on today and see if I can get my modules stable, I never used anything higher than 1.65v VDimm because of the Intel specification, but I have read a lot of posts on here where people are running 1.8 to 2v VDimm without any issues.

Do you know why Intel have said that 1.65 is the limit?

Having them running at their rated speed with only 1.58v is not bad actually.

What did you have the advanced timings set to when testing these clocks, did you just leave them on auto?

I always set my advanced timings to the same values as the XMP profile sets them to, I haven't actually tried playing around with these yet.. I just have mine set to 8-7-7-21-1T atm, and it is stable with the CPU at 4GHz, I let it run 20 passes of LinX using all available RAM, and I left it running Prime95 Blend Test overnight to, and it was still going when I got up this morning, so I would say that this is stable.