Leads?

[NARD]

Does repacing all your plug leads with performance ones make any difference?;)

[MOMO]

replacing your current plugs with "hotter" plug will always help.

[Blackcoog]

Unless you have issues with your current plugs you will not gain any noticeable improvement on a NA engine. I have seen improvements in supercharged/turboed cars but on a Cougar you can't expect to see much if anything. Stick with what you have or if they are higher mileage replace them with a set of double platinum Autolites or stock plugs.

[NARD]

Just put a set of performance leads on and there really is a noticable difference in smoothness of the ride (unless I'm just wishfully imagineing it).:):)

[Blackcoog]

If your previous wires were bad/old then it would increase the smoothness of the ride. :)