Any functional differance betwwen the HEI factory coil with red/white wires and the red/yellow wires? Thanks, Kevin:TU:
Yes, there is a difference. Otherwise GM would not have sold both kinds. One is "wound" in the reverse direction from the other. The wire color is an identifier, but the coils are identical in terms of spark output. This is done to syncronize the magnetic polarity of the ignition coil to the polarity of the pickup coil. I suspect the difference is that some GM engine families spin the distributor clockwise, and others spin the distributor counter-clockwise. Either coil will fit inside the cap, and either may spark. BUT there is a risk of hard starting and/or backfiring when starting if the wrong coil is used. Source: http://www.mrgasket.com/mainfaq.html Further research: Delco service bulletin 1.2D-27, dated 12-1-75, and napaonline.com Olds except Toro, Buick, share same pickup coil. (yes, I know a Buick V-6 won't have the same part number pickup coil as a V-8, but these pickups use a Blue tag or black connector body on the pickup coil wires.) Chevy, Caddy, Olds Toro share same pickup coil (Yellow tag or yellow connector) Therefore, direction of distributor rotation would seem to have no effect on which pickup coil is used. Pontiac uses a different pickup coil. (Clear tag or connector) HOWEVER, napaonline shows Chevy and Cadillac using one ignition coil/pickup coil set, and all Buick, Olds using the other pickup coil and ignition coil set. Pontiac uses a different pickup coil but the Buick/Olds ignition coil. No change for Toronado, vs. other Olds. First guess: NAPA is selling the wrong coils to Toronado owners. It would be best to use the correct coil sets for the application, but I cannot figure out any logic for selecting one set over another set. Distributor rotation is the same on a Toronado as on a Ninety-Eight, but Delco specifies different pickup coils for the two applications.
