Just checked my book. Stock America shocks are 12 1/2 inch which is 1/2 inch lower than stock Bonnie with cast wheels.
Give it a try if you can. At least you'll know if you want to go 1/2 or 1 inch lower. That's assuming your 412's are stock height. Just measure from eyelet to eyelet (center) and you'll know for sure.
KOF
