55312 When I put my car togeather and wired everything up I had the same problem A brand new 6al box. If the ground wire is not on a GOOD ground location or tight you will blow the shunt in the box. The test will pass but the car will not run. I sent mine back to MSD and it was repaired at no charge. What coil are you running? You cann't run any coil on that system. You need the HV one for street. The others will burn up internally. You will get the same problem, good spark on test but car will not run. I have spare 6AL box and distributor module that stay in the car with the tools to change them. I would buy a new box and pickup. replace one part at a time. It will run again and keep these spare parts for the future in the trunk just in case.
Rick Lake