I am in the process of changing the front bumper on my 280z to the smaller 240z bumper. I bought repop bumpers and the swap brackets from z car depot. I also bought a used front valance and grill for a 240z.  The bumpers , brackets and the front valance all fit good. My problem is the 240z grill .   The grill will not fit unless I cut the louvers to slide through the bumper brackets as I see it. If someone has a better idea I would love to hear about it. I am in the process of painting my car so cutting and welding would be no problem. Thanks in advance Ken 

A 240Z grill has the lower three bars shorter at each end to allow for the bumper brackets.  Does your grill look like this?

Keep in mind the shorter bars are for the usual position of the bumper brackets on a 240Z.  Since your car is a 280Z the conversion brackets may not be in the same location.  If you don't want to cut the grill bars, consider disassembling the grill and swapping short and long bars to accommodate where your bumper brackets are located.

thanks Jim I will give that a try