I was looking at a used manifold for a B16 and when we put flange side that attaches to the head on top a flat metal area, I can see that it is not as flat as it should be. it goes up on one side by more than a hair, not noticeable until you really look at it hard. My question is, is that too much warp already?? is there an acceptable warp??

 

it will not work well at all if it is warped. If you need it decked, we can do it for you.