Ok, got it stable now, it's the L740B126



It is with open window for some minutes. At 24°C ambiant, it is as hot on 2 cores as with my previous L734A at same 3.6GHz but with 1.424 real vcore instead of 1.334v forr this one

So, despite the lower vcore, it heats quiet the same as a per clock reference. The delta between cores is up to 7°C usually. I'll try to reseat in few days with some MX-2, then I'll try a vertical mount of my WB. If nothing do it, I could lap it