Long time lurker, first time poster. I would like to install two vanities along a long wall which previously had one single sink right in the center. The supply lines are not an issue but the drain is because it drops down into a concrete slab foundation. So what I would like to do is install a 90-degree fitting on the existing stub out (shorten the stub first, of course) facing left and put a second sanitary tee above or below the one for existing stub out, then use another 90 degree fitting taking that pipe to the right. Then 90-degree fittings at the end of each new run (about 24") to exit the wall. Hope this makes sense! I then planned to use 2x2" lumber to fir out the wall to 2x6 dimension with voids for the new drain pipe to pass through. Am I crazy? Any other ideas? Thanks in advance for your help.