The Charger, 300, Challenger and Magnum were all on the same LX platform. Only difference was the body panels. Yes early 5.7 had MDS, 345 hp. My Magnum got 25 mph highway all day long. Im not sure if it changed later, but I know at least initially the SRT 6.1 did NOT have MDS so you used quite a bit more gas. You could not totally turn off traction control, but pulling its fuse in the front fusebox would let you lay down as much rubber as you wanted. I think the 300 took a LOT of its styling from the then new Bentley. The 5.7 Hemi got better fuel milage than the 3.7 V6. Part of that was because the V6s only had 4 spd autos while all the Hemis had 5 spd. Aftermarket like Indy Cylinder Heads, sells crate engines with both the 392 and 426 cu in displacements. They even make kits for 4 bbl, dual 4 bbls or Weber type FI. A friend even had a twin turbo kit installed with both turbos at the rear end....realllllllly quick.
[This message has been edited by rogergarrison (edited 09-23-2014).]