If all of my 8 exhaust valves were leaking badly can that cause high crank case pressure? Along with a warped head in the center?

 

valve stem sleeves ware will cause combustion chamber air to enter into head area to cause crank case pressure.

 

I currently got the head back from the shop, they fixed the leaking exhaust valves and they resurfaced my head and shaved the warped spot so its like a brand new head. Its all cleaned out and valves are like new plus shiny flat edge so hopefully that fixed the problem.

 

What acmech said. Def can cause high crank pressure