While trying to get to know my 96' DI better, I came across 2 vacume lines that don't connect to anything on the top end. They are both located right behind the rear end of the passenger side valve cover, and they're both curved on the ends.

Is this normal?

 

I believe that those are actually vent lines ( don't cap them off !)

 

Here is a pic, you can see the two curved top vacume lines among the plug wires and A/C lines.

 

Probably your transmission breather lines.

 

Vent lines? Ok, what do they vent?

 

All your oil boxes have breather tubes, oil gets hot and the air expands. Breather tubes let the pressure equalize and not blow out seals. Also check your differential/axle breather tubes to make sure they are not clogged. This should be part of your regular maintenance.

 

Ok, thanks for the tips, I'll put that on the list.