RJ45 is a keyed 8-position jack, not a normal 8-position jack. ("Keyed" means that there's a notch in the side making it a different shape; you would not be able to fit an "Ethernet" connector into it.)

Closer is RJ38X, which is a series 8-position jack, not a normal 8-position jack. ("Series" means that the jack shorts pint 1 to pin 4 and pin 5 to pin 8 when there's not a cable plugged in to it; you would be able to fit an "Ethernet" connector into it, but even so it's probably not what you want.)

AFAICT (skimming 47 CFR part 68, and the historical AT&T documents that became 47 CFR part 68), there is no RJ-number for a normal 8-position jack.