Missing hole under water pump

lonewolf41

Petty Officer 2nd Class
Joined
Jun 28, 2013
Messages
150
I am transferring my water pump from my old block to my new block. Both are 878 castings (5.0GXi motor), but my old block has an extra hole for the water pump that the new block does not have. Is this an issue? The water pump has the hole. The old block in the pics is red. The new one is black. TIA.
 

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pae0332

Cadet
Joined
Jun 8, 2017
Messages
27
don;t worry about it, the big hole is were the water flows. as long as the pump fits properly and does not hit the timing cover
 

lonewolf41

Petty Officer 2nd Class
Joined
Jun 28, 2013
Messages
150
don;t worry about it, the big hole is were the water flows. as long as the pump fits properly and does not hit the timing cover
That was my thought, but just couldn't figure out why it wasn't there. I have never seen a chevy block without this hole. Some car forums seem to indicate it is to relieve pressure during cold starts when the thermostat is closed. Probably not relevant to marine where we have the bypass in the water neck. Thanks.
 
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