I have an 86' F-250 with a 460 4bbl auto trans in it, Its getting gas and has a good coil plugs and wires it just is not getting fire when i turn it over (plugs dont spark). The truck ran fine when I parked it but when I went to start it up it did this to me and the distributor is clean the only thing I think it could be is the brain or ignition box (small gray box on right inner fenderwell), any opinions on this would be greatly appreciated!