Great work! Sounds like a fun build!
Shorter struts should just be some homework to figure out what works...
Does a mustang have the shock inside a tube, with the tube having the bracket for the spindle? Or is the does the shock itself have the spindle bracket welded on it?
If it is the first case you could do like people in the E30 ( the 80s BMW 3 series like mine) and "stanceworks" world do to lower a car further than the bump stops... Just shorten the tube and stick in a shorter shock... LIke here...
http://www.stanceworks.com/forums/sh...ad.php?t=22708 Or here...
http://www.stanceworks.com/forums/sh...ad.php?t=20850
http://www.r3vlimited.com/board/showthread.php?t=233644 These are bag installs mostly but a coil would fit similarly in a bag's place...
Is there something in the spindle preventing you from just cutting the spindle bracket off the shock and rewelding it higher?
Food for thought, probably useless for your uses but there is
always a solution to the problem.