Lots of issues and variables here.
First an '86 is not late offset. The 85.5 & 86 cars had the later aluminum arm front and rear, but were still early offset. The 87 & 88 cars were late offset.
Early steel arm cars 83-85.0 used rear spacers from the factory, and early offset wheels. If you put either the spacers, or early offset wheels on a 87+ car, you will go over max track width. If you put the spacers on an 85.5-86, and use early offset, you'll go over as well. This is why we have a rule!
How you measure it, and even rear camber, can affect things to a degree.
If you are at 67", your setup is correct.