Ok stick with me here.:D
Just in front of the block (where the threads in the block are) you can drill a small hole through the aluminum timing cover into the bolts hole.
This will let you spray a lubricant into that bolt channel in the casting without affecting anything else.
The lube will be contained between the bolt threads in the block and the bolt head on the front of the water pump.
Once the bolt is out that little hole in the casting won’t affect a thing.
Sometimes those bolts are corroded up the shoulder as well, and the above method can help that also if that is the case.
I give the bolt head a few smacks with a hammer to help shock the threads loose.
It works most of the time and is easy to try.
