Hey Mike, just do an inventory of your ECU's and post them. Hoppy will know which ones are good brands. If they are untested, you will have to screw them on and run them but I wouldn't want to wear the screw holes out in your firewall from changing them out so many times. They are just sheet metal screws in raw metal. Could cause a bad ground after so many swaps. That's where Hoppy's ECU testers make good sense.