1973challenger360, I'll answer what I can:
*First, pick your trans. It will need to have a B/E body tailshaft (dual mounting locations) to fit your Challenger.
*Now you have to match your clutch/pressure plate selection to the input spline count of your trans (either 23 spline or Hemi 18 spline trans (much more $$ for the Hemi box)).
*Your flywheel choice will be dependant upon your clutch selection (Clutch/pressure plate types: 10.5, 10.95, or 11 inch; diaphram, borg & beck, or long style).
*Your bellhousing will have to fit your flywheel/clutch/pressure plate assembly - 10.5 & 10.95 vs. the 11 inch set-ups.
*Buy a shifter, either aftermarket or a used Chrysler E-body Pistol Grip. But c'mon, we're Mopar people here, so a Pistol Grip is the cool looking way to go. You will also need the shifter rods and the shifter rod lever "tabs" and small hardware for the shifter rod linkage.
*Get an E-body pedal set-up. I don't know if any B or A body stuff will work in an E-body, so maybe somebody else on this board can answer that.
*Get a clutch torque shaft (also known as a Z-bar in GM language).
*Frame brackets for the torque shaft
*Get the clutch rod kit and release bearing lever kit from Mopar Performance. There are differences between small and big block kits, so get the right one.
*Cut the floor out carefully to fit your used or new manual transmission hump.
*I don't have my reference books with me, but I
think you need a
longer driveshaft for a manual trans. Mopar Peformance sells kits that you will have to have cut/balanced at a drivetrain shop. Or you can search the swap meets.
*You will have to make sure your crankshaft has been drilled out for the pilot bushing required for the input shaft of the manual trans.
Now, where do you get this stuff. Beside the aforementioned swap meets searches, you can try the usual restoration sources such as Jim's Auto Parts, Koller Dodge, Mancini's, Jack's Auto Parts, Layson's, Year One, or the Paddock. But for
my transmission specific needs, I would try:
*Brewers Performance, Inc at 937-698-4259. They have things like small rebuild parts for transmissions, shifter linkage kits, torque shafts, floor humps, shifters.
*Imperial Services at
www.imperialservices.net or at 989-652-6309. They seem to have the smaller bits and pieces for the shift linkage. Check 'em out thoroughly, because I did not get the chance to.
*Keisler Automotive Engineering. They can sell you
everything you need to go from an automatic to a
5 or 4-speed set-up. They sell everything the first two guys sell as well as pedal set-ups. From Richard Ehrehnberg's articles in Mopar Action, these guys look to have high quality stuff.
*Auto Body Specialties (
www.autobodyspecialt.com or 888-277-1960) for a transmission hump.
*Harms at
www.surprisegarage.com for shifters, trans humps and other stuff.
I hope this helps. If any other people on this site can offer additional advice, correct my mistakes, mention other suppliers, or sell you the stuff you need, please step up to the plate.
Larry