vr6 turbo spark plugs thoughts ideas?? Best plug concept..

[higahardy]

alright today i check the plugs on my Megasqurited vr6t to see how my tuning is coming along!!!

I noticed that my front plugs are pretty much perfect light grey, but my rear bank is super rich almost fouled... now i know my fueling needs more work my thought is too run a hotter plug on that rear bank to compensate for the richness and a colder plug one on the front bank.. any pros or cons to this since i'm running stand alone with direct fire gm two tower style msd coils????