Dual Tank Hoses

[new84k20]

Hello First off I'm new today!
My question is am I missing something at my dual tank selector valve as it isn't as simple a fix as everyone is telling me. I have replaced all the short rubber lines going into the valve and coming out (6 hose) but it seems to me that the one hose was an odd size. Should they all be either 3/8 or 5/16 because that was what was there from the start? However, the nipple on the valve in one location on the feed side was smaller than the 3/8 but not 5/16 so what the heck is going on? It is just rubber hose and the valve right? Anyone got good pics I cannot believe I can't pull this off....

 

[SlickGTP]

I recently put mine together and remember there being one 3/8"(primary) and one 1/4"(return hose, also if I remember correctly). The vapor hose was 5/16" if I remember correctly and each tank T's into one line that goes up to the front, but I'd have to climb back under the truck to be certain.

I realized it after I got the truck started after finishing the job and having it pee fuel all over the ground right before I took it out for a spin. Not fun when you're putting tools away and letting the engine warm up only to turn around and see a huge puddle under the truck. lol