I always run Autolite coppers on all my vehicles - but it seems the only plugs listed for the 5.7 are platniums and iridiums.
What will give me the best spark? Anyone know? The platniums always had a weak spark in the past in my opinion - the older cars always ran better with the OLD worn out plugs rather than new plats.
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70 Duster - Keith Black 526, 2 x 830 annulars/tunnel ram, big solid roller, 727 ProTrans, Strange 4.30s
77 440 Dodge van 12.96 @ 108 - 4800 lbs of love with a 2.72 peg leg and 1800 stall
74 cheyenne 452 stroker, 2x450's on a tunnel ram, 21 foot, Berkeley jet, place diverter
Platinums and iridiums are sperior for a fuel injected, closed loop combustion chamber were air-fuel ratios and temperatures are better controlled. They have issues were cooler t-stats and rich air-fuel ratios leave carbon and soot deposits.
The older exposed electrode type spark plug works better for dirty combustion chambers were soot and carbon are more likely to accumulate.
Run the recommended plug, assuming your 5.7 is still fuel injected and closed loop. They'll last much longer and give better overall performance for the higher compression of the later model engines such as new hemi. If it has a carburetor then consider a traditional spark plug.
MSD used to tell you NOT to run platinum, I always noticed harder starting with them, but I guess the newer systems are deisgned to use them, plus they tend to last a little linger and dont erode as fast. I know people that are running over 100000 miles with original plugs in their new hemis.
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