The front of a sweater has a lower neckline than the back, so you have to start the neckline shaping sooner than you did for the back.
You'll knit until the front is 18 rows shorter than the back, and then begin your front neck shaping.
"Trust the pattern!"
Time flies like an arrow, but fruit flies like a banana.
Hop aboard while we follow the cloud-covered van of knitting harmony, man!! Woooo!! --He