I'm told this is a rear carb for a '58 392 Hemi as used on the letter cars (Chrysler 300D), can't find any info on the 300 sites, various Carter guys on Google, forwardlook.com, etc.
There's gotta be a listing somewhere that can confirm what the application was; anyone know?
Thanks in advance!

According to Ackerson's Chrysler 300 book, 58 300D's ran a WCFB 2741S in front, and WCFB 2742 rear.

Steve,2534S is 57 300C front.I have Carter books back to 1951 if you ever need any more info.

And this says a WCFB 2534S is a front carb for a 1957 300C:

http://www.chrysler300club.com/rcmstuff/carbs/ccarb/c.html

And if you're interested, here's all the carb numbers for all the letter 300's:

http://www.chrysler300club.com/rcmstuff/carbsbyyear.html

Thanks, you guys, I appreciate the info.
'57 300C, though the date code is a puzzler.
I managed to stumble across similar info from the 300 guys by Googling it backwards ("2534S Carter").