Anyone know much about 50's dodge cars?

Not to sound stoopid, but what's an FMJ k member? and why would you want to change it out? You can fit a small block or a big block into the existing one with probably less fabbing than putting in a new K-frame,A-arms, etc, they are quite spacious. AAJ Brakes makes disc conversion kits for those cars too. An 8 3/4 should fit pretty well into the stock springs etc out back. I've only seen one 50's Dodge site, it's called www.forwardlook.net it's all early Dodge, Plymouth, Chrysler and DeSoto related, mostly 55-61, but there are some even older models on there. Good luck. If you get the 54, post some pics.