Hey all, I have a 2002 sport trac 4.0. I need to find replacement cams. I can only find ones for 2004 and up. The part numbers for mine are 7L2Z-6250-C and 7L2Z-6250-D. The 2004 and up are 7L2Z-6250-A and 7L2Z-6250-B. Does anyone know what the difference is or if they would be compatible? Looking for master tech advice.