Depending on which "later" distributor you have, getting it rebuilt or sending it in as a core to the outfit
Kultulz posted the link to, there aren't many Made in the USA choices.
Mallory used to make a couple pretty nice Y-block distributors, including one with tach drive, but it's been discontinued for about 5+ yrs.
https://www.amazon.com/Mallory-USA-3...ct_top?ie=UTF8
The original Mallory ignition parts company doesn't even exist anymore.
Both of my project Birds use an oem '57 distributor so the '57-'59 version is the one I'm familiar with. Although the oem '59 to '64 Y-block distributors could work just as well for you.
There are still a few independent shops around that can rebuild (& recurve as needed) the one you have.
Caution: an exchange distributor from an auto parts store supplier may get you an incorrect distributor with a main shaft that is too short, which can fail quickly.
Other than the newer carb and dist, does your 312 have any performance upgrades, or is it stock?
Which intake manifold is on it? ECZ-A ('56) or ECZ-B ('57 style)