Garden Orientation

[HBKitmitto]

I'm hoping to get some advice on how I lay out my garden and my garden rows this year. I've got a 40' x 40' garden that is sloped running south on the high end and north on the low end. In the past I've always run my rows going east to west but I'm wondering this year, is that best? If I run my tomato rows north to south, will that work better for sunlight? Does it even really matter? I may be completely over thinking this.