It became one of those major overhaul type of jobs. It was on jack stands for 4 months in my Dad's pole barn upstate. New brakes all around (all hardware and parking brake hardware included), tranny flush, rear header replacement, engine mounts, struts, rear sway bar mounts, replace (make) rear brake line, drop gas tank, both new front wheel hub assemblies, new ball joints... oh yeah, you asked a question.
YES, the engine clatter was gone when I finally got to start the engine. To save time I'll just say the driveshaft and rear mount assembly came out as one from the transmission and it was pressed out at a local machine shop and repressed with the new one.

 

cool story. thanks much. sounds like what i get into when i do a 'simple' job on my 63 impala...
tony