I just added some performance parts to my 1993 5.0 HO and have a problem I cant figure out. The rebuilt motor will not start to save its life on the 302 HO firing order but it will fire on the old 289 firing order. What is going on here? I installed iron gt-40 heads, B303 cam, Gt40 upper and lower intake, 65 mm throttle body, 70 mm mass air and 24# injectors. Any help would be appreciated I am completely stumped.