Isn't the 64 dodge custom 880 a C body? If so, maybe a stock C body setup from later years ? For the front at least.
Cbody platform didn't start until 65. A 64 Custom 880 would be pretty much identical chassis wise to a 64 Chrysler.
That being said, you might be able to coax a Cbody bar in there but I think they were undersized for the original application and while better than no bar, for the same amount of effort, you can get something sized more appropriate.
I've heard the GM pickup bars from the 70's-80's are a better choice diameter wise and can be modified to fit fairly easily.
Kevin