Can I use my Ford transmission?
Yes. Diesel Conversion Specialists® currently makes 15 different Adapter Plates that allow you to bolt a Ford transmission up to a Cummins engine. Ford transmissions work better in the conversion because they are OEM equipment and well known to be among the best transmissions available. Even if you don't mind a bit of fabricating to use a lesser transmission be advised; some of the older, 1997 and later, trucks use a cable to drive the speedometer creating another potentially costly hurdle to overcome if you want your factory instrument cluster to work.