i just finished changing my plugs ..when i bought the truck it had 70,000 miles on it, so i pulled a plug then and checked it, it looked brand new to me, so i just put it back in and left what was in there,i didnt even pay attention to the brand at the time, well i found out as of today i had the autolite 5224 in there no probs to me, so i bought the champion 4436 truck plugs and changed them tonight , did notice a little better throttle reponse , but thats a new plug talking, i will let you know how they work out,( under my hood on the emmissions sticker it said RC12LC4 plugs ), the old 5224 still had plenty of life left in them after 32,000 miles, i gapped the old ones and they were still .044 or lesscompared to the .040 stock new, truck now has 102,000, so all in all the 5224 is not a bad plug, i kept them just incase the new ones suck

 

Big engines don't seem to be bad on plugs. I had a 400 in that pontiac to your left and it did great on plugs. The first plug change I did on my Ram (360ci)was at 127! They looked great. This summer I am doing a 'big' tune up.

My 89 (273?) Dakota went throught a set a year to pass inspection and they were black. I probably needed a hotter plug. 90 My Carvan only got one change as you had to jack it up and crawl under and thread those things blind.

If I understand it correctly, an MSD 6a system fires the plugs three times? per cycle instead of once, so it wears everything out quicker. I wonder if it increases MPG due to better burning?

 

i was suprised how good they looked, im going to get a better coil and wires , gonna have to search on here to see which is the best coil to use...... help burn up that extra fuel maybe??

 

They will tell you MSD or Taylor 8.5mm wires, Mopar Brass performance distrubutor cap and rotor, and an MSD or Accell coil. Search the site. Autolite 5923 plugs faced toward the injector. Some of those things are pricey. The wires go for $80.00! So you may want to buy a component at a time.

I would like to see an mpg study on the 6a ignition.