[part.cfg] attachRules = 1,1,1,0,1 or 1,1,1,1,1

[zer0Kerbal]

should change [part.cfg] attachRules = 1,1,1,0,1 or 1,1,1,1,1 to 1,1,1,1,0

These are the AttachRules, in the same order as the AttachRules entry:

* Stack
* Surface Attach
* Allow Stack
* Allow Surface Attach
* Allow Collisions

Rules 1 and 2 define how this part will connect to others. Rules 3 and 4 define how other parts will connect to this one (provided their own rules allow it). Rule 5 is a special case that defines whether or not a part can be placed while intersecting another.