[Hotrodhornet]

I would do whatever I could to make it drop straight down the 3" hole to avoid any blockage, when I get to my coach I will take some pics of the flange I used to bolt onto the top of the tank, the pipe slips into the flange just like assembling PVC pipe, I used the not hardening pipe dope in case I ever have to disassemble it for some reason. 
I went to the Texas r v in San Antonio and told the gentleman what I was trying to do, he had both flanges in stock, the hardest part of the deal was drilling the hole. Paul