72 Demon slanty-to-340 Resto

I hope that works out for you. If not a C body tube can be made into an A body one by Moser Engineering for you.
Funny enough, I'm seeing a listing for a 8.75" from a 69 Newport (C body if I'm correct) with a 489 piece in it 1969 Chrysler Newport Convertible ~ 8 3/4 ~ Rearend - No: 2881489 if nothing else, maybe a backup axle?