12 valve breathers

Anyone have a successful method of putting breathers into the SIDE of 12 valve covers that don't leak? Right now I'm planning on having 1/2" ports tig'd into the sides, and running tubes into a larger catch can with breather filter things in it, mounted right next to the grid heater.

Pictures would be nice also.

If you're having them welded, they aren't going to leak? But I would use a 90* facing up so your not just pouring all your oil out the side of the valve covers

This is mine on my 99fummins one line off the side plate the other is off the front cover