the A518 (46RH or RE) was used behind 318 and 360 trucks/vans since the early 90's. The A618 (47RH/RE or 48RE) was used behind the Cummins Turbo Diesel and V10's in trucks, it has more torque capacity stock, but you can build a 46RH/RE to have the same specs as the 47/48.
Some extra info,
RH = Rear wheel drive, Hydraulic control (i.e. mechanical governor)
RE = Rear wheel drive, Electronic control (electronic governor, i.e. governor solenoid on valve body) started around 1996 I think? TacTransman will have better info...
The diesel case will require modifications to mate to a small or big block via a different bellhousing or adapter plate. The diesel case may require additional surgery to fit in an ebody
The hydraulically controlled transmissions are easier to adapt than the electronic controlled ones
A website for more info:
http://www.transmissioncenter.net/dodge.htmhttp://www.tcsproducts.com/There are also some threads on the site about this swap...
http://www.cuda-challenger.com/cc/index.php?topic=23678.0I got mine off craigslist for $300, if you have wrecking yards like pick and pull, you might be able to score one for less.
If you are planning to rebuild it yourself, figure between 800-1200 bucks for parts, converter and special tools (there are some special tools to disassemble the overdrive portion and setup the thrust plate clearances). Terry (TacTransMan) could give you some options on having yours built.
Also figure between 300 - 500 to adapt it to fit your 440. Plus whatever time and parts it will take to make it fit into your car.