You'll probably be fine with the 7mm, but those guys must be full of crap. The wires don't even get near the hood at any point on a 4.0 or 4.6, they run around from the back, not over the top, of the intake. I could see how they might have to cross over the intake on a distributor type 3.9, but I don't remember for sure.

 

Your right, but everyplace I checked said they were special order and would take up to 2 weeks to get them in. This is my d.d. and I don't wanna drive it with the misfires. But I completely agree I should have got the 8's

 

I will have them pressure test it, could this be the cause of any misfires?