I'm planning to replace my 60x30 cast iron bathtub in my 1960's home. The depth of the existing framing is 32.5". Is there any reason why I shouldn't install a 32" bathtub? I'm planning to install a solid surface surround like Onyx. I realize the finishing work may be a headache leaving only a .5" to work with, but I'm not sure if there's anything else I'm not thinking of. Thanks!