Any idea how thick the timing cover is behind the water pump?

Pulled the water pump off the 70 340 yesterday, and like I've seen on others there is some eroded spots on the timing chain cover directly behind where the impeller sits. Doesn't seem too bad but it got me thinking how thick the cover is in that area? If someone has a loose one and a big enough micrometer could you measure it? Or maybe someone already knows. Maybe its as thick as the area around the water passages? Thanks!