Hi... I have 100% stock '86 GT V6 and I would like to install Champion Spark plugs, RV15YC4. Does someone know what the gap should be? Thank you.

Stock gap on the V6 is 0.045, but I'd highly recommend using AC Delco R42TS plugs.

oh oh... I bought Champions. Delco is the better way to go? I can switch to the Delco's.

Can you tell me if I made another mistake? I ordered an MSD cap and rotor and coil. I thought they would be a little upgrade. The coil is supposed to fire a higher voltage. What do you think?

I have the MSD coil on my car, and at least in my case it works better at higher rpm's, above 3000 or so. The MSD cap and rotor are good pieces, too. Definitely swap out the Champions for AC Delcos.

... rather amusing that I, given the choice between two plugs, chose the less recommended ones. I think I may have done the same with spark plug wires... I bought some STI's... sheesh! Thank you for the info.

A while back I bought some (very expensive) Bosch spark plugs. After getting advice from several members on the forum I swapped them for AC Delco plugs. The ECM is designed to work with the Delco plugs, and doesn't take advantage of the 'features' of the more expensive plugs, so if you're 100% stock, they will work best. My car has been running great with Delco plugs, lots of pep and decent gas mileage too.

Stock AC Delco plugs will work the best. Early GM engine control systems had limitations and made decisions on fuel and timing based off of some known parameters not the least of which is fuel burn duration and heat. When you change to a non stock spark plug you change these and the ECM doesn’t know it’s different. I spend a lot of time in the early to late 80’s fixing “it just doesn’t feel right” complaints be replacing newly installed aftermarket spark plugs with AC Delco ones. Do yourself a huge favor and put in the stock AC Delco plugs.