Oh yeah. He said he had a new drive shaft for it as well. But he has to look for it. But that's for a duster but I'm guessing it'll work on my dart swinger.
You will need a 727 specific converter because 904 converter is different. There is also the issue of external balance weight used on 5.9 Magnums, which is different than the 360 LA engines. The correct B&M flexplate can fix that with a neutral converter either way.
As for driveshafts, his won't work because a Duster (Demon and Dart Sport ) has a 108" wheelbase while the Swinger has a 111" wheelbase! Rear u-joint size can be different too - 7260 vs 7290.