fordmuscle

I would have to agree just use the Motor Craft Plugs. That way if you have any type of problem you can go to a local parts store and fix it.

03BottleFedGT

autolight ap104 same as motorcraft and has longer threads reduces chance for blowout

99BlackPonyGT

the threads in the head are the problem, not the spark plug.....just sayin

stang315hp

Thanks for the help, what do you mean blowout? What's the best way to get 20hp more out of this car? Thanks again.

MJH78

Some of these modular engines during certain model years are known to "spit" plugs out because of a lack of sufficient threads in the head for the spark plug. On your other question, most people will recommend upgrading your ring and pinion gears to a 3.73 or 4.10 and getting a tune.

stang315hp

I already have a chip and tune, but what about underdrive pulley's? (my crankshaft one is rusted anyway) I still think though that better plugs should give a better spark even if it's avery small difference it''s still a difference is it not? In this regard, which one's would you pick. (blow-out safe) THANK GUYS.

MJH78

There's no "blow-out safe" spark plug. A motorcraft plug is all you need, but if you feel you need something different, go right ahead and waste your money. What is it you want from the car and how much money do you have budgeted? Underdrive pulleys are not your answer for performance gains.