Is there a way to install a switch that you could toggle that would make the MDS stay on, therefore forcing it to be a 4 cyl until u flipped it back to 8 cyl? Reason I ask I seen on the new camaro that this will be an option. Has anyone heard of doing this?

 

Nope, can't be done...

 

Actually, the MDS is controlled by the PCM, although I don't think you could control it with a switch, you could control when it comes on & off with the proper software modification.
I believe MDS on/off was going to be a feature of the Diablo Tuner that has not hit the market yet. Now over a year after it's promised delivery date...