ARP sell single replacement studs. Their tech support number is listed on their website and is very knowledgeable and friendly. I have spoken to them MANY times!
You need to dry those holes 101% before putting those studs in, with a rag, with a vauum, turning the block upside down, what ever you can do. And you don't need me to tell you this, but building a serious engine, 4am and 5% operational brain is a BAD mix my friend.
Good luck.
Yasin