Smoke from breathers.

I am having the same problem with my motor. A leak down test is what I would do. I recently compression tested my motor and had about 224 psi each cylinder (according to my guage), give or take 1 or 2 psi. So everything "seemed" good. But a leak down showed every cylinder was about 4-8% except my #8 which was 14%. I was having some detonation problems and didn't know it at the time, but it caused the motor to start smoking out of the valve cover breather and right side exhaust when revved up. The air seemed to all leak past the rings on #8 through the crankcase so it may be a cracked ring or something. Who knows until I get it apart. Get the leak down tester, hook it up to your air compressor, set your #1 cylinder at TDC on the compression stroke so the valves are closed, make sure you have a wrench on your crank so it doesn't rotate, test at 100psi, rotate the crank 90 degrees, and go to the next cylinder in the firing order, repeat. 1-8-4-3-6-5-7-2