My grills in my 1970 cutlass look crooked ( slope lower in the middle ) , I looked at pictures on flea bay, and most of those grills slop too! and I noticed the front bumpers don't run parallel with the bottom of head lights ( I have not tried to put my bumper on yet ) is this common ? The grills only bolt one way. right!

 

I had the same problem with the sloped grilles. I finally figured out it was due to core support damage (the grille center mounting point bracket was bent). I put in an undamaged core support and now I don't have the problem.

Regarding the bumper versus the headlights. My OEM bumper fit correctly. I bought another bumper, still in GM packaging, had it rechromed and installed. It droops versus the headlights and doesn't line up with the reliefs in the fender.

On a related note, my new GM front fenders, still in GM packaging had the lower mounting brackets welded in an incorrect position. The shop had to cut the brackets and reweld.

The explanation I was given was that when GM had poor fitting parts, they took them off the assembly line and put them in the Parts Warehouse. That is also a possible reason why our bumpers don't fit right at the headlights.

 

The bumper should run perfectly parallel with the headlights. Many front bumpers have been pushed in at the center so slight that you can't tell but it makes the ends not correct with the headlights. The front bumper is also very difficult to get lined up exactly like it is supposed to be but id it is bent at all then it adds to the frustration. For the grills, Sometimes it is an illusion that they are not straight but I have found some that do not line up like you think they should. The Supreme and 442 grills always look way off when taking a picture from a low angle.