"My reply about adding 400m to 3700 was a short answer to the...

"My reply about adding 400m to 3700 was a short answer to the post from ?????? sorry can't find the poster,
whom implied that because the drill as been upgraded, should be able to go deeper."

Luciano, as far as I know the upgrades to the rig were primarily to the mud system which doesn't generally have any bearing on how deep the rig can drill. Maximum drill depth of the rig is generally governed by the drill pipe hauling and handling components (drawworks, top drive, mast drill pipe capacity etc). Pump specs can also be a factor.

From memory the maximum depth they could go to on M1 was dictated by the amount of drill pipe they had at hand rather than theoretical capacity of the rig.