Gallien-Krueger 400rb?

[Kro]

I use this rack ears on a 400RB-II, 200RB, 200RCB and a 1200SEB. These amps have approximately the same outer dimensions:
View attachment 3463293
At the 200RB and the 200RCB I had to made holes for the screws.

Hard to argue with that - any shots of your 400 with the ears from the front or the side? I saw the shot of them on your page from the top.