Gary,
Isn't this what they called "Variable Displacement", as in the Cadillac V8-6-4 back in the 80's? Those worked by disabling the lifters so that both the intake and exhaust valves stayed closed when the engine was lightly loaded, but they came back in under acceleration. Here's a link that explains the details, and it does mention an aftermarket supplier that tried it for a while. Variable displacement - Wikipedia, the free encyclopedia