ok, i know there are speial "Leading" and "Trailing" plugs. the "Leading" go on the bottom, and the "Trailing" go on the top, but what were to happen if they got mixed up. or they were installed backwards? So the "Leading" where on the top and the "trailing" were on the bottom.. what kind of effects would it have? would i tcause ne long term damage?

 

it wouldnt really hurt the motor per say. its mostly a temp range thing I THINK. heck some ppl here run 8 or 9's all around

 

summer weekends are slow on the forum - everyone's driving, or fixing their cars I'll see if I remember this correctly, and someone can feel free to jump all over it if I don't.
The L & T plugs aren't physically different (as in, one is not longer threaded, for example, such that it might stick into the chamber if put in the wrong hole).They are different temperature ranges. Since the lead plug fires twice as often, it is a cooler plug. Running them swapped will mainly affect plug life, and possibly mileage and emissions slightly. Putting the hotter trailing plug where it sees more action (leading) will lead to quicker wear, and the leads already wear faster. The cooler lead plug in the trailing location may tend to foul due to not running hot enough to burn off deposits.