What is the best, hands-down spark plugs I can put in my 1992 GMC Sierra full size truck? It has throttle body, 350 engine, AC, Power everything...loaded...etc.

I have Autolite platinum at present but they seem to "miss" at idle. Under power there is no apparent miss.

I would really like to change these Autolites out to something that would be considered the best for this truck.

Thanks! Chuckwagon

 

DENSO IRIDIUM PLUGS ARE REALLY GOOD PLUGS BUT THEY COST MORE,I THINK YOU SHOULD GO WITH AC DELCO SINCE IT IS AGMC AND THEY ARE CHEAPER,AND YOU MIGHT NEED TO UPGRADE YOUR WIRES TOO,

 

I seen on HP TV the ep3's or something like that gave 7hp gain and 2 mpg on the dyno Im going to try them.

 

Ep3's? where would I get those?

 

I got them at advanced Auto put them in today they rock. Felt the difference right away.

 

7 bucks each but if its true you make that back in gas

 

Have you noticed any improvement in MPG since you installed the new plugs?

 

I ran Bosch Platinum plugs(the regular plugs not the Bosch 4 plugs) in my 1990 C1500 Chevy Silverado with a 5.7 350. I also put a cap androtor and a new set of Factory plugs on it. It did seem to have a miss at idle also, but never hit a lick. We just figured it was due to the Edelbrock intake, JBA headers, ASP underdrive pulleys, Hypertech Themomaster chip, 160 Degree thermostat, K & N filterand an exhaust sytem from a muffler shop with a glass pack that made it seem like a miss. And I later designed and built a ram air setup for itthat made a hell of a difference. The ram air used the stock air box. All I did was notch the air box spacer unde the box and turn the air cleaner with the air tube facing the drivers headlight and the tube from an 1985 chevy truck was used to attach the air box to the air catch tube that was attached to the radiator core support with a holecut in it. The air was drawn through the hole and directed upwardby the way of the metal tube angled upward. I never had any problems with rain or anything.The plugs did increase the MPG.

 

Yeah but I also did other things. I had trans issues.