I have an 89 xlt,and my rear sprigs have seen their best days.
I live in sweden and the access to Bronco spare-parts r werry limited.
The access to chevy Blazer parts however is mutch better.
So my q is if the leafsprings from a Blazer fitts on a Bronco..the veichles r much built the same.

blazer leafs are approx 3in shorter than bronco springs (IIRC), so it wouldn't work. they are also a half in narrower. see if you can find a 4x4 f150 to get springs from

or, get the chevy 63" springs and move the spring perch back. Another issue is the chevy springs are 2.5" wide instead of 3, so you would need some spacers or different hangers, like out of a ranger or explorer I think