good morning. I have a ZZ4 engine in my truck that runs just fine. I am removing the 650 carb and adding a FAST EFI (30227-kit) and would like to add an MSD box but am not sure if I should get the 6AL or the EFi model? Also, is there anything else you would recommend (i.e. why would I want to upgrade to the VK6ALSSKIT kit?)

Thank you.