Well well, one step forward and 2 steps back again...
A trip to the hardware store and then wrap up a few loose ends then decided to put the bed back on to see how far out the back the hitch sits when using the one existing hole in the bottom of the frame. I picked up the bed and got the dunnage out of the area and backed the truck into place, lowered the bed down and got it aligned as good as possible then relaxed the lift. It took me a while to figure out why the bed just wouldn't slide that last inch to get back into place....
Before i raised the tank the vent was low enough that it was under the bed cross member, guess i forgot about that when raising the tank, even worse if you look at the pic's where the cross member sits it was plain as day.. Oh well
So I had to lift the bed back up, pull back out from under it, remove the hitch and unbolt the tank from the frame and fuel line, reposition the tank forward while using a 2X4 to gauge the clearance to the vent (yes a 2X4 is 1.5" and the cross member is 1.75") then take measurements from the rear of the frame to the tank, pull the tank back out and reposition underneath the frame and transfer the mounting holes from the tank back to the frame and put it all back together again then re bend the fuel line a bit and shorten and re flair it. The tank was moved forward about 1 1/4".
I also decided the hitch could be moved rearward almost another inch if i plugged the two existing 3/4" holes in the frame and re drill all 6 holes. Welcome to my welding booth complete with wet dirt ground, yea its been dumping all day again and the water leaches back under the cover. Oh my 220V extension cord had to be run from the garage outside and under the car cover too. The pic shows the top which was welded first then ground flush, then welded from the bottom.