My son's '85 Plymouth Reliant needs the redesigned carburetor, #4342890. Does anyone how + where to get one?

#1.. I would go to auto zone. NAPA or one of other "bigger" auto parts stores, and order, - if not available,- then I woud try dealer (parts store will be cheaper than agency dealer)! If that doesn't work try eBay!--- I ume you don't already have this on car?? Otherwise you could send one you have in, and have it "rebuilt"!