Curious... you think a 70 Challenger would fare better at those insane speeds than a 68 Charger? All else being equal (even weight)? Its definitely a more slippery design...
stock for stock, hard to say. Both have crappy recessed grills. The Charger also has the recessed back light, but does have extra wheelbase, which is a factor in stability.
I'm sure you can reasonably easily dig up aero numbers on the classic Chargers since they evolved into the 500s and then the Daytonas. Classic Challengers are a bit harder to come by, but since they have the SCCA history, I'm sure there are figures out there for them as well.
As shown here, it only takes a few mods to give them some capability for high speed. With creative application of those mods,they could be made streetable without being too ugly. Yeah, that big slab of a nose cover helped the aero, but it is butt ugly, IMO. A flush mount grill with close knit mesh for the grill opening would look better and still provide a significant aero gain.
