That's a dangerously high offset. That means that 0.35 V will be added to the VID (the voltage that the CPU requests from the MB based on the current operating conditions). For example if your VID is 1.35 V under load, you will get 1.70 V (+/- some based on LLC settings) on the CPU!
The 1.385 V reading you quoted is most likely at or close to idle. Using offset voltage (along with EIST and C1e) allows the voltage to drop when idling. You should be getting around 1 V at idle.
If you desire 1.385 V under load, then you need to set the offset appropriately for that. Find your VID under load using a monitoring program such as RealTemp. Note that VID is not the same as Vcore! Subtract the VID from your desired load Vcore, and this will give you the offset you need (it may even be negative!). Enter this value in BIOS and adjust it as needed until you reach the desired Vcore.
If you have instability at idle, then reduce LLC a little and increase the offset to compensate.
The process of setting up an offset OC is a bit tedious, but the results are worth it. I have two 2600K's running offset OC's, one of which has been running that way since March of last year. They run cool and quiet at idle and handle any load I throw at them (including folding@home).