Fly: <<Any estimated weight it takes to get the plane to balance a 6.5" with a ys up front?>>

You could probably cut a hatch, put the battery near the tail and add no weight. On a Dazzler I built, I made the entire bottom of the plane removable so I could juggle components. I put a Saito .72 on it and the battery is almost to the horiz stab - but required no dead weight. I was expecting to add weight on the UCD for the Saito 100 and was going to cut a hatch and juggle back the battery. Whew... no need!

Desertrat: Thanks for the comment on the checkerboard. I thought I would add "something" to set it apart.

kirbster: If you go through the mongo threads, you'll probably see references to flooding (during idling), flow while fueling, pumps, and regulators (one reason some favor the YS). Those posts will reference the potential problems you'll possibly see. Others say they have no problems. I didn't want the potential headaches so I mounted 90 degrees. If you plan on keeping the tank where it is, I don't think you'll be able to lower it in the fuse without scooting it back. I think one of the formers keeps it from dropping down in the fuse (in the current position). Even so, you'll have to pull it back enough to get the stopper out of the firewall and then allow enough room for the lines to clear. Stock tank fit is great if you decide to use that. I installed the rear support and siliconed it there and at the firewall to absorb any vibration and it worked great.

-s