According to the chart I have, that number ID's a NWC T5 from a '84-'87 "S" truck, either 2.5L L4 or 2.8 V6. It could have either of two ratio sets:
RPO ML3:
1st 4.03
2nd 2.37
3rd 1.49
4th 1.00
5th 0.73
RPO ML4:
1st 3.76
2nd 2.18
3rd 1.42
4th 1.00
5th 0.73
You'll have to do what Gearhead describes to ID the 1st gear ratio. Let us know what you've got!
