if you measure the width of the hood and grill, and theres not that distance between the fenders at the proper points, yu got something wrong!
don't worry about the back of the hood until yu've got the front close, and able to latch properly
sure you've got all the right parts? everything needs to be assembled loosely so it can all be moved around - as Ken sez, the manual will insure you haven't got anything in wrong, or left anything out, then it all needs to be shuffled and tightened a bit at a time
Bill