I have what they used call the 1.0, it's only good to 650 hp so I had to remove some stickers on the GP. I am using the MSD 85551 now but I also have the MSD E curve that I might drop in since that can be used with or without the box. The E Curve sets up the same way with it holding back the timing so if the box ever died, like MSD boxes have a habit of doing, I would just have to change a few wires and settings on the dials in the distributor and I'd be on my way