I got mine from Mancini Racing. they are all pretty much the same size, whether it's for a Coronet or a Challenger. They all run about $40 whether it's from Mancini or on Ebay. I bought mine at Mancini's display at the mopar nats, so i saved the shipping $!

Make sure you buy one for a fender, as the grill emblems are not adhesive backed.