Unless its a 4x4 or you are doing a ton of heavy towing I don't agree with the above calls for the 4500 over the 3500. The 4500 has a granny first, so unless you are towing or off roading its really only a 3 speed + overdrive. The NV3500 has a 4:1 first so its still pretty deep, but is actually useable on the street. The 3500 also shifts nicer and is actually pretty sporty with the hurst shifter setup.

In a 2wd application, especially a fairly light vehicle like a 46 dodge, the 3500 will be plenty strong with a street 360 unless you are planning big slicks and drag launches. That said, if youare planning big slicks and drag launches you really really wouldn't want the 4500 either!

So I guess what I'm trying to say is, tell us more about the project and what your goals are and it will be easier to recommend a trans.

-Jon