what would be some good performance spark plugs for my 97 mustang gt 4.6L and any body have an answer 2 why my tranny is poping out of reverse and what would be some good little horsepower adders for my car like headers and umm

 

I just bought and installed some +4 Iridium Spark Plugs by Bosch, and I can really feel the difference in response, and a better idle.(from .8 RPM to a clean .5RPM)
They run for about $10 per plug, but I think it's worth it. Better ask one of the more experienced members for the other stuff..[&:]

 

Autolite 764's for a 1.50 each!

 

Spark plugs = ZERO performance increase. All the +4, silver. platinum, iridium are gimmicks for cars that did NOT originally come with them. Theyre trying to make money off of your inexperience, and hope youre too stupid to ask anyone with actual knowledge on the subject.
The ONLY time you would EVER need a different spark plug is if youre going to run nitrous or forced induction. And even then you dont need the +4 (which I wouldnt wish on my worst enemy) or iridium (maybe for EXTREME applications), you would just need a different heat range so the plugs dont melt because of the extra heat in the combustion chamber.

Mustangcat - if your car starts running like absolute ****, change back to the original equipment plug. The +4 plugs are horrible, and its possible that your car just needed a tuneup at the time and thats why you noticed a change. I installed a set of +4 (at my bro's request) in his BMW 325IS, after about a month his car ran really rough and would have a misfire at low rpm's. I switched to the OE plug (which happend to be 2 prong silver), cleared his misfire right up. Hes had those plugs in there for 40K with no problems whatsoever.
-P.

 

Of course I will. But when I did change my plugs to a better brand/better material I did notice better response and it solved my high idle, the original plugs were in pretty bad shape too, can't argue with results P Zero.[8D]