What he said
Challengers are not light cars even stripped out slantycars.
Slantys belong in 2800 pound or less cars. Not 3600 pounds plus porkers by the time yur in it with A/C on. Yur gonna need monster gears to go with that clutch, and a close-ratio 4-speed to work with the powerband this beast would require.
IMO the whole idea ..........is, how shall we say it kindly... needs more thought. Howzat?
You wanna 6; use 4.7,Magnum, 5-speed