With enough money and time it would not be totally impossible, but one needs to ask the quest as to why bother.
Better options exist instead of attempting morph parts onto something that was never intended to be morphed...
If you are seeking over drive then you might be further ahead to add a overdrive unit and be done with it.
Check out Gear Vendors for one manufacturer...
GEAR VENDORS OVER DRIVE UNITThey also make an under drive unit which allows you to drop your gear ratio on the axles to get better mileage when the power is not needed. When you need the extra power you stomp the under drive switch and you have a new gear ratio to work with.
Either way much better than attempting to adapt a 90s transmission to a older engine/vehicle..