I know I can get the MSD to work I have 2 of them on 6.1 based engines now running great. The issue with the XIM is I cannot control the timing. No matter where you set the dials it has 32 degrees of timing. I fooled with it for 6 hours today I could get the idle timing as low as 16 degrees but as soon as it got off idle it went straight to 32 degrees no matter where I set the max timing dial. I tried 2 boxes and both did the same. I think it is the way the XIM interprets the crank signal, however Fast subbed out the software development and none of the engineers there knows the strategy or they don't care but I can't get an answer.