the crank can only realy go any where on its down stroke as the upper part of the block is too thick to push through and the crancks inertia dosnt go to the side as strongly

the best way would be as chip says an intergrated ladder section with through bolts holding it together

the problem is that the block cant take through bolts at all because of the oil ways .the only way round this is to rethink it all together making id different to the yb all together