New Battery Slightly Larger Than Previous

[fivecodys]

I bought a new 12V Deep Cycle battery (27) to replace my failing original battery(27) that came with the trailer.
The new battery is slightly larger (physically) than the old one.
It fits very tight in the battery box.
The battery box is located in the basement of the fiver.
The lid of the box will not fit down over the new battery.
It only goes down about 3/4 of the way.
This box has a vent hose in the top and a drain in the bottom.
Any reason for concern here?

Thanks in advance for the response.

Bill