New 6Spd behind an old diesel possible?

[DieselFumes]

been driving and using the troopy a lot lately and have come to like chugging along at 2400 rpm for cruising, and mostly getting passed on higher speed roads. the granny is perfect with my set up, and there maybe a better hybrid setup, the truck performs as it should, possibly better than expected in 4x and does it well. A very thought out vehicle as factory set imo and with my added 33" tires and small lift it is just right. I really only need another 8-10 mph and just doesn't seem worth it.

Think I'm gonna put this idea to bed for a different build. Thanks for the input.