It all depends on what you do with your car. I've run the O/D with a Commando 273 and a souped up 170 and loved it. If you were drag racing or road racing it would not be a good choice. It is nice to be able to cruise at a decent rpm and not cobble your car up. I've even advised someone, running a 440 sixpac "B" Body how to run it and he loved it.