Well, you would have to decide which is more important, the right sound or the right cam to make your car a good performing daily driver. Before changing the cam, it would be good to determine the condition of the rest of the engine, is the bottom end still tight? How's the compression on the cylinders? 70K isn't a lot of miles on a 305, but it's not worth investing money in an engine that has a cylinder or two with low compression, or the bottom end is just worn out from lack of proper oil changes. Also does the car have an automatic or manual tranny?