If you're looking to run sanctioned events,check with the various organizations' online rule books(usually download-able). NHRA will allow you to "build" a car to a certain combination per engine size,rated horsepower(their rating,not Ma Mopar's),shipping weight;all OEM/factory-built combinations,though. In the case of the Charger(that would be cool in Stock Eliminator),you'd have at least a couple of small-block combo's and a number of big-block variations to consider. There's also the matter of what your competition in a given class is running;some classes may have a particular car that can bomb a record if needed,but doesn't,and can almost "rule" a class.
Something else to consider: today's "Stock" class cars are truly smoked over and a hell of a lot tricker($$$!!!$$$!!!) than meets the eye. No cheap or even inexpensive enterprise here. If you were just running local tracks for fun,you might not run into a "killer" car in your class,then again,you might. A good measure of your car is how it fares against the proven cars.
MANY years ago,I had considered using the Faubel car body(before I discovered what I had) to build an A/SA Max Wedge car(might have fit into B with a steel front end and 11:1 mill) for local running and MAYBE a bigger event. Then,I talked to some people. People who had raced and were racing. They asked me if I ate paint chips as a child. Yeah,their words were not too encouraging. They loved the racing and development,but hated the politics,got tired of the travel,and plain burned out. When the fun factor diminishes,well...
Not trying to discourage you,but just offering an opinion. There's lots of SERIOUS racers here that can offer better advice than me.