GM HEI distributor...need to know what color wire is what
 

I'm installing a MSD Digital 6 box and it replaces the ignition module with a pair of wires that plug into the original wires that plug into the module. There's a cream wire and a green wire. Which wire is positive and which is negative?

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1990 GTA
-355 carb'd, nicely reworked '64 vette heads, 2500 stall, 4.10's, other small things.
-Alston SFC's, Eibach Pro-kit, Koni's all around
-100+ nitrous shot
-Cruising in style with leather and nice stereo.

please guys, I can't find my chilton's anywhere.