Why are trucks come with 7.5 mm right?

 

And why is that?

 

I think the stockers were 7mm

 

Thicker wires = less propensity for arcing and predetonation. Of course, a higher quality 7.5mm wire will beat an el cheapo 8mm wire. A general rule is the less ohmic resistance the better, as the electrical charge will take the path of least resistance and hopefully that's down the wire and not thru the insulation to another wire. With a cheap set of wires with bad crimps, it might be easier for the spark to jump to a less resistant wire, believe it or not.

 

Most of the wires are 40-50 ohms.

 

Dammit. Now i'm all conflicted again. Son of a bitch...

 

It worked better for me over the Accell cap & rotor. It lasted longer than the brass for some reason. My setup at the time was the MSD off-road box with the off-road coil, autolite 3923's, MSD 8.5 wires.

and beyond the ignition... 52mm fastman, crower 1.7 RR's, Modded kegger, gibson shorties into the stock y-pipe into a dual out flowmaster set to 2.25" (keeps low end torque up).

 

100% true... stock wires are 8~10k ohms & up/ft... the MSD's are 40~50/ft

 

When should you replace plugs, wires, cap and coil?

 

Alright. I think I'll give it a try. Mopar performance stuff seems to be quality in general.
Thanks for your input Steve.