I wanted to know if it was possible to place a D-Tuna on a 7 string original floyd and not have MAJOR problems.

I just happend to think that instead of using multiple guitars, i could buy one 7 string with an original floyd and be able to dump the low E to a D and just use it as a 6 string drop D guitar mid set, just worrying a bit if the low B would just totally annihilate the tuning of the other 6 strings