Custom 115 gallon!!!

Well the top side plumbing is in along with the sand! I'm taking things Über slow because I've been so busy but steadily coming along. [attachment=0]ImageUploadedByTapatalk1351359715.428924.jpg[/attachment]
 
So I have a question... My tank is drilled on the bottom and I have a large overflow, now I am thinking about drilling the rear near the top instead, any thoughts? My tank has two 1 1/2" drains and 3 1/2" returns. Id be doing this to regain the space the overflow consumes... Thanks!
 
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