Tank location... yep... you can cut the cross piece from the bottom of one former and install the tank under the tube...

You can also install it above the tube and cut the former out of the hatch (and move it forward to maintain strength) so if you use the pipe you can still center the tank on CG.

Cut 2" off the plane eh? True to your RCU handle... Well as they say... uh.... "Good luck with that."