Anthony,

On the FULL SIZE the tank sits between the spars and the tank top overlaps the spars and ribs about 1" to 1-1/2". The leading edge is sheeted with aluminum back to the forward spar. The Paul Matt YMF/UMF drawings indicate that this distance is about 5-1/2". The attached pic is of a YKS top wing (with out tank) to give you an idea on how it all fits. The YKS wing is constructed similar to the YMF wing.