C5AE A with holes in the water jacket

[Realrundell]

I'm looking at C5AE A block that has two holes in the water jacket. One is near the starter and the other just ahead of the mount bosses on the right side. The holes approximately 3/8 in diameter. Can these be repaired?

[jayb]

I wouldn't be afraid of fixing those, I've fixed way worse than that.  You could get them welded up by a cast iron welding place (see the link below), or find a way to plug them.  If the material is thick enough you can drill the holes oversize and tap them for a pipe thread and seal them up that way.  If the area is too thin for threads, you could fabricate a plate that goes over the holes and use very small screws around the outside to hold the plate in place, then seal the plate to the block with something like JB Weld.  On first use I think I would use some Moroso Ceramic Seal in the water jacket to address any potential weeping around the repair.  If the block is worth saving, go ahead with the repair.

https://www.castmetalwelding.com/

[Realrundell]

Thanks for the input. The rest of the block appears to be in good shape. It's .030 over, bores look good. The owner is a long time professional welder and states he has repaired blocks in the past explaining the labor intensive procedure. I was a bit concerned about the hole near the starter as that area appears a bit thin. He did agree to allow a sonic and pressure test after he has done the repair, so I guess we shall see.