So I have an MSD ignition in the car now with 8mm wires. I have to replace them cuz a few of the wires are bad. Will 7mm replacements be ok?

 

no...you want the wire with the least resit....I think msd has some 50 ohm ones

 

The thickness of the insulation and the wire resistance are not related. To answer the question, you should use at least 8MM wires with a powerful ignition. The diff between the two is the insulation which you need more of with more juice. A 7MM wire will have more tendency to bleed through and potentially crossfire with other wires.

 

I picked up a set of Accel 8mm SuperStock wires. 450 F resistance. 3,000-7,000 ohms per foot resistance.

 

not good...my wires has 25 ohms per foot..... so you basically have wasted your money on the msd

 

I didn't waste any money. I didn't even buy the MSD. Personally I think they're garbage.