Like everyone has said, reverse eye spring slight drop with stock axle, drop axle with stock spring more of a drop and reversed eye spring WITH a drop axle is on the ground
. I've used Anson and Okie Joes (Sids doesn't do 28-36, he sends them to Joe's)...it depends who your close to.
If you do go the drop axle route make sure you send your axle AND spindles to Sid so he can drop your spindles to your axle.
Also original Ford axles and spindles are the ONLY way to go.