I don't know that I agree with the above recommendations. For what would normally be considered a truck cam then yes 100% agree, but an off road sand dune racer or mud racer you will be spinning the engine a lot higher. Low RPM torque is not in your best interest here. Now rock climbing, pulling a trailer or general dirt trail driving is a different story. With all the gear available in a 4WD vehicle the extra RPMs are very useable. As for the converter I know a stock 11" converter from a HP BB car works fine with the MP 284 cam.
I have a Comp Nostalgia Plus cam in my Power Wagon with a 360 right now and love it but it is a 4 speed and has 4.10 gears.