Sclor, that,s 87 & back. There is a tag on one of the bolts that hold the tail housing on. Get the number off this tag that has 1352-xxx. Go to Mongo,s garage website & bring up the chart that gives the gear ratio,s. You want one from the mid 80,s that has the .072 o-drive ratio. The .086 would not be enough to be worth while.