I have a 87 blazer with a tbi 5.7 and i want to put on an MSD cap and rotor. not like i think its gonna make my truck faster but the cap and rotor need to be replaced and i trust the MSD name plus the red cap will match my wires. anyway i'm not sure what part numbers i need. summit is vauge with there descriptions. i think i need cap (MSD-8426) and rotor (MSD-8410) but i'm not sure. any help?