oil tank

This thread is a bit of the beaten track but here goes.
I have built a offroad single seat buggy and have powered it with an xt engine (of course).
Now the issue being the oil tank that i fabricated is under constant pressure from the return oil line bringing back oil/air.

I tried running a breather of the tank but due to vibration and rough ride the oil found its way up the breather.

I then cut the top off the tank and put a baffle blate under the breather fitting (exits at the top) as well as adding a bit more
height into the tank.

However the oil still managed to find its way into the breater and spew out every where.

Dont know whether to block the breather of all together and let the tank run under pressure??(the tanks on the bikes dont have one)
Or run the breather of the top of the rocker box to the tank,which then poses the problem of having oil push up the breather and into the rocker box

On the bike the rocker box breather does go into the tank via a tube but does not look like it could get oil fed back into it as it sits up fairly high away from the oil level.

If i plug the breather in the tank i am not sure what will happen to the oil flow as the tank will be pressurized.

Any ideas??