My H22 block has gotten a few nicks and dings in the head mating surface since it's been in my garage, and I was wondering how deep or how much does it take before you need to have the block decked?

I was going to use that copper spray stuff that helps seal head gaskets and transfer heat, but is there anything else I could use that may prevent me from having to get it decked?

 

It depends where the nicks are and how deep they are. If they are near the outside of the block and no journals are around them you should be ok. If they are between cylinders, between oil and coolant journals, get it decked. If they are really fine scratches, I wouldn't worry too much, but if you can feel it by running your finger nail over it, deck it. Its better to do it now, than not and having a leak later on.