Which Spark Plug
 

Right now I have bosch platnuim spark plugs in my 5.0, should I change them out I was reading that NGK is good which part number NGK's should I use

Platinum = long life (not high performance)

Copper core = high performance

The copper core NGK plugs have excellent quality. I don't know what part number plug for stock heads. I run Autolite copper core plugs. They have very good quality and they are inexpensive. I change plugs so often (several times per racing season) that I can't justify spending more than $1.18/plug.

Autolite part number 25 will work well with stock heads and no power adder. If you're supercharged or spraying nitrous oxide, step down a heat range or two (24's or 23's).

I always use autolite or motorcraft. I tried the bosch once (for a couple days), and it ran like crap. since then nothing but motorcraft.

Autolite
 

3924's...solid, even with a bad valve guide or seal they still fire strong.