im sure someone more knowledgable will chime in soon enough, but in the mean time...
according to my service manual, the bronco had a few different rear axle set ups dependant on the respective axle code found on the door tag;
<TABLE style="WIDTH: 223pt; BORDER-COLLAPSE: collapse" border=0 cellSpacing=0 cellPadding=0 width=297><COLGROUP><COL style="WIDTH: 64pt; mso-width-source: userset; mso-width-alt: 3108" width=85><COL style="WIDTH: 48pt" span=2 width=64><COL style="WIDTH: 63pt; mso-width-source: userset; mso-width-alt: 3072" width=84><TBODY><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; WIDTH: 64pt; HEIGHT: 15pt; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65 height=20 width=85></TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; WIDTH: 96pt; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl66 width=128 colSpan=2>
Bronco</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; WIDTH: 63pt; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65 width=84></TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; HEIGHT: 15pt; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65 height=20>
Regular Axle</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
Ratio</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
Rating</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
Locking Axle</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; HEIGHT: 15pt; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65 height=20>
03</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
4.11:1</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
2780 lbs</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
A3</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; HEIGHT: 15pt; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65 height=20>
04</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
4.57:1</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
2780 lbs</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
A4</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; HEIGHT: 15pt; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65 height=20>
05</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
4.11:1</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
3300 lbs</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
A5</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; HEIGHT: 15pt; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65 height=20>
06</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
4.57:1</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
3300 lbs</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
A6</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; HEIGHT: 15pt; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65 height=20>
18</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
3.50:1</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
2780 lbs</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
B8</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; HEIGHT: 15pt; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65 height=20>
19</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
3.50:1</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
3300 lbs</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
B9</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; HEIGHT: 15pt; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" height=20></TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1"></TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1"></TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1"></TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; HEIGHT: 15pt; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65 height=20></TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl66 colSpan=2>
Econoline</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65></TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; HEIGHT: 15pt; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65 height=20>
Regular Axle</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
Ratio</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
Rating</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
Locking Axle</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; HEIGHT: 15pt; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65 height=20>
01</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
3.50:1</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
2300 lbs</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
-</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; HEIGHT: 15pt; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65 height=20>
02</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
4.00:1</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
2300 lbs</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
-</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; HEIGHT: 15pt; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65 height=20>
07</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
3.00:1</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
3050 lbs</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
A7</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; HEIGHT: 15pt; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65 height=20>
11</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
3.50:1</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
3050 lbs</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
B1</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; HEIGHT: 15pt; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65 height=20>
12</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
4.11:1</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
3050 lbs</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
B2</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; HEIGHT: 15pt; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65 height=20>
13</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
4.57:1</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
3050 lbs</TD><TD style="BORDER-BOTTOM: #8399b1; BORDER-LEFT: #8399b1; BACKGROUND-COLOR: transparent; BORDER-TOP: #8399b1; BORDER-RIGHT: #8399b1" class=xl65>
B3</TD></TR></TBODY></TABLE>
so basically what i'm asking for clarifiaction is; which axle did you put in your pickup?
hope this helps you to learn a bit more about your swap