'68 Dart with a 318 LA - Build Options
Another vote for a 360 Magnum. With the 3.58 inch stroke its a poor mans small block stroker. The bigger stroke is like using a longer wrench to loosen a bolt instead of a shorter wrench. A lot more leverage to turn that crank resulting in a superior driving experience. So its not the extra cubes its that leverage to move the heavy street car. The bigger bore also allows the heads to breath a lot better. You'll be able to get away with less rear gear and less converter too another plus.
If it was my car 360 Magnum dressed up to look like a 340.