I am going to be switching out the 406 I have in my 67 for another one I just bought. The only thing I know about the motor is what I was told by the last owner. When I got it it had just break in miles on it and was told it was a 406 with around 330-340hp at the crank. I have had the intake and valve cover off and it does look as though it is fresh. It runs very well and I had planed on at least doing some heads and a cam. I just happened on the new motor and for what I got it for I felt it was the better option. So what could I get out of my old? If it will not bring much I will just roll it back in the corner of the garage and keep it.