I also did mine 5" and 7"
front- 3" springs-2" spindles
rear--5" springs-2" block (slightly shaved and angled for pinion)
I C-notched the frame along with an adjustable panhard bar.
The top of the rear is actually closer to the bed wood than the rear to the C-notch. I have about 3" from the rear to the wood. No problems though
20" wheels all the way around