Please please please make sure all of the bolt holes are DRY!!! If there is water in them then your block will CRACK, cause you can't compress water lol. Use lots of compressed air and brake cleaner to clean them up.
I know what you mean about expensive. The only reason I got them is because if I ever need to take the heads off whether its for bad luck or good reason lol I can take them off again and reuse the bolts.