NGK spark plug question
 

I see the UR45 is the stock replacement spark plug for the 87-93 5.0 with stock heads but can I use a UR5, a cooler plug since I'm running a wet NOS system?

Re: NGK spark plug question
 

Yes, but remember that running a cooler plug for the nitrous is beneficial when on the spray, so if you are a daily driver that sees only an occasional WOT punch with the juice, I would recommend staying in the stock temp range, but if you are a braket racer or it's a race car only, run the cooler plugs. Eitherway, it's a "safe" plug to run.