7.8hp briggs and stratton ohv valve vent hose?

I installed new larger lifters and the valve cover wont fit down flush now. I can make it sit flush if I remove the inner guard inside the valve cover that leads to the vent hose? Looks like a piece of sheet metal siliconed onto the top area of the overhead valve cover. Can oil get into this vent hose? Where exactly does the vent hose go? Someone said it would be fine as they THOUGHT it went back to the crankcase but was wanting to make for sure from someone who knew. I have searched for the exact lifters but not one place I went to had them or could order them. I have a 14hp kohler motor and the lifters were identical fit, just a little taller and thicker. I figured since this motor is on a generator and runs constant (ALOT OF HOURS) that bigger lifters would benefit me since I already had one get hot and break. Any one have any knowledge on this please help? Thanks