While a differential is not absolutely necessary, it will definitely provide a better driving car.  So I have decided to go with a Peerless differential with a 1” OD x 38” long unit available from Staton Inc. for $195.  Steve Vinson did a great video showing how the differential marries to a sprocket via an adaptor at one end and a disc brake at the other.  I have purchased the adaptor from Renegade as the one Steve recommended is no longer offered at this time.

At present, I plan on a 60-tooth sprocket on the axle, with a 10-tooth sprocket on the TAV using #41 chain.  I used #41 chain on my boat tug project and was impressed with its strength.  I also bought rear axle hubs from Renegade and am picking them up at the Huntsville Grand Pre race this weekend.  I hope to see how many used this combination at the races and how well they performed.  While attending the Hunstville Grand Prix, I confirmed to myself that the differential was the right choice for me.