Getting Rid Of The Oil In The Valve Covers

Would it be possible to drill & tap the front of a brad head to accept an # 8 a/n fitting and run it back to the oil tank? The purpose to suck the oil out of the valve covers, Run two # 8 lines one from each head to a # 10 that's tapped into the oil tank, I`m thinking that the suction and gravity would keep the valve covers dry? Shimmy