Running your timings @Vertex_FR seems to work well. I had TRFC set lower, and TRAS set to 68; TFAW 16, other than that, about the same.
Here is my first spin at 7600. VSA was absolutely my limiting factor; +25 offset required for 7400, +100 offset required for 7600. I'd like to get CPU VDD2 down a bit. I have the PMIC mode set to auto. CPU VDD/2 set to 1.25/1.55, mem VDD/VDDQ set to 1.62 bios, which results in 1.545 on one stick, and 1.56 on the other.