I've had the clips off of a few of my trucks. I never tried to remove them whole. Thinking back, I suppose you can, but are you going to benefit in any way if you do?
I actually have two trucks with complete front clips. One is a parts truck and the other is a truck I am cosmetically restoring. The truck I am restoring does not have that great of a front clip but my parts truck does so for ease of reference and minimizing the risk of losing bolts and screws, I thought I would keep the (not so good) clip together to look at when reassembling the restored parts from the other truck....??