I can't believe I'm actually "attempting" educating or helping you
If it's just a stock rebuild restoration either
Accurate Exhaust {Mopar Specialists}
http://www.accurateltd.com/What-did-the-factory-exhaust-look-like_ep_40.html
or TTI Exhaust are direct bolt-ins
http://www.ttiexhaust.com/Category-ClassicExhaust/ComponentParts.htm#ep
both are in the upper price range but both are guaranteed
& both will fit very well & represent the OE stuff the best
I actually like the Flowmaster stuff, I've had great luck with it,
but my cars aren't stock either & I like the sounds/exhaust note
I use the Delta 50's & mandrel bent pipes but I'm making enough HP
to justify using the larger mandrel bent tubing & a performance scavenger mufflers...
Where most go wrong is, don't go
too big of pipe,
especially if it's a stock 383ci, 2-1/4" to 2-1/2" tubing is plenty big,
even on a 440ci unless your making well over 450HP-500hp
also use a H-Pipe or X-Pipe & you won't have the resonance/drone issues...