rear suspension design help needed

[wedged]

I played around with the crude CAD drawing, keeping the rails between the tires at 30" O-O and the rails in front of the tires at 38" O-O. I was able to make the upper bars have a 23" effective length with a 70 degree included angle. The actual length was 28". Would 28.75" be a good length for the lowers- that makes the upper effective length 80% of lowers ?

In the drawing, the frame starts to widen from 30" to 38" at a point 18" in front of the axle centerline for clearing the 29" diameter tires.

This may sound weird, but I'm getting excited about the possibility that this is going to work out well.