I recently checked a spark plug that were AC Delco R45TS gaped at.045 and saw that they had a white or grayish color on them so I decided to change them and go with Autilite Platinum AP26 I also gaped them at .045. After I was done I took it for a test drive and I could feel a little bit of a miss or stagger as I accelerated. The wires are older but they worked fine before. Is it the plugs I used?

did you change the plugs 1 at a time to make sure you didnt mess up the firing order on the wires?

HEI wires are very touchy. Usually, if you mess with them after about 50K miles to change plugs or move things around, you damage the wires and get a miss like this. I always try to change my plugs the first time at around 40K miles or less so the wires survive the second set of plugs. Then the next time around, I replace both the wires and the plugs and start over completely.

Had the same problem on my pickup truck after changing to platinum tip plugs. Popped the hood one night and an electric light show was going on under the hood. I had recently changed wires but they didn't take kindly to the yanking and twisting when I replaced the plugs.

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79 Z28 Bought new, honeymoon ride, same wife, same car.

I changed each plug one at a time so the order is right. The plug wires are old anyway so I think I'll change them too. Any suggestions on wires???

I changed each plug one at a time so the order is right. The plug wires are old anyway so I think I'll change them too. Any suggestions on wires???