That’s a vent to the transmission, not the crank case. The Trask cover vents the crank case.

 

So no more venting through the stock head breathers once the Trask unit is installed. Interesting.

 

The stock head breathers still vent but according to trask they are not adequate especially if you’ve added cubic inches to the stock motor, their cover provides the vent needed for larger displacements

 

So the Trask breather is an enhancement to the stock breathers not a replacement.

 

my interpretation is the Trask cover is intended to be a preventative solution to reduce or eliminate the head breather combustion residue by relieving pressure elsewhere rendering the head breathers not being needed as much...the head breathers still serve the intended purpose they always have, just folks choose to reroute the mix of emissions elsewhere as a reactive 'solution' instead of being re-combusted mucking up the top end and causing excessive external dribble as well....like many aftermarket inventions they are building a better mouse trap to improve perceived OEM issues..some of the time they are successful, some times they are making money marketing things owners don't need

 

I opted to stay with the stock breathers on my 131" although I added a second small O-ring to help with sealing when I installed them. I also left my original homemade breather bypass in place since it was just some water vapor coming through the hose when I keep my oil level at 1/2 way on the dip stick and using the latest Harley oil pump.
If things get messy I'll look into the Trask.

 

I'm really surprised @ how much water vapor I get

 

The Trask cover maintains the trans vent, which is item 12 in the parts diagram you posted, and adds a separate vent for the crankcase.

 

I shouldn't have waited, lol.

 

Looks like it was a hit! I’m glad I grabbed mine at their tent in Daytona, plus got very nice discount!