On my '90 LBCC dually, my '86 single wheel, my '88 single wheel, as well as both U-Hauls, & my other Fords they are all 3" wide.
My '85 CCLB Dually Chev has IIRC 2 1/2" wide rear springs.
Don't remember without going out to look how many leaves on them all.
10 leaf sounds like a lot, unless they...