Best motor for 69 Barracuda

100% 340 or 360. The 360 is going to be easier to find and you can dress it up to look like a 340 if you are interested in a period correct look. No one would know the difference. If you have the ability, the ideal would be to find a mid 90's or so Dodge Ram with a 360 magnum in it and put the fuel injected engine in that car with a really mild cam. Of course you would have to be able to tailor the wiring harness and computer (I think there is someone here that sells a plug and play) and add an electric fuel pump and return. A little more work, but a great setup. That would be a great running car with the convenience of the modern electronics!