all those holes look like they could be tapped for tapered pipe plugs, providing of course, they are somewhat close to the hole size of "??" required for "??" pipe thread. example, drill size for 1/4" NPT is 7/16". you could then use square head aluminum pipe plugs with a good sealant [JB weld perhaps ?], then cut/grind the plug[s] flush with the casting surface.
lots of work involved though, to do this.
hopefully, you didn't pay much for that intake. unless, of course, you want/decide to use it on an LA block.