I wouldn't twist the original paint scheme up on that car or put anything, other than a 67 383 in it. Any 66 date code 383 will be good to go.
Black is nice, but if you don't paint cars, it's not easy. That car is extremely rare and it would be mistaken for a '68 or '69 with a bumblebee stripe.
The car also has the GT trim, which I don't think would carry well with the stripe. If I'm not mistaken, a Scat Pack stripe car never got any kind of trim, going front to back on the car.
Any other dart, per se. slant six, 318 or anything else with a clutch in it would be fun with a 360 and some custom work, but I personally wouldn't do that to a 1/500 car. Especially not one that still had it's trim and everything that made it rare.