Will an AC bumper for 400EX fit on a 300EX

[Quadfather]

will it?

[muff]

yes and no

the bottom mounts will fit on perfect, and the top will line up straight BUT the top of the 400ex mount is wider then the 300 top mount, you can either bend the mount brackets and risk breaking the welds, or get some spacers and use some long bolts to hold it on but this wouldnt be real strong because of the length of the bolt needed