Becareful what you buy. Those are cheaper private label cores not GM OEM cores even though on top says "acdelco part number". You do see these as "replacement parts" on Ebay but they are not GM OEM cores.
I dont accept those in for OEM core trades or have them ported and send them out to you guys for usage. That's why I tell guys it has to be an GM OEM core. Its not worth the "misunderstanding" later.
Now if you buy one of those cores and wanted that throttle body ported, it can done, but it just takes a little longer.