i need to change my plugs. i have about 6 bottles on a set of TR6's, but i have a set of 104's here at the house. i kinda want to change them tomorrow, but to get TR6's i have to order them. i really don't know what heat range a 104 is compared to the NGK TR6. is it okay for my 150 shot? or should i wait on the TR6?
thanks in advance.

 

The 104's are two steps colder than stock.

 

thanks steve. so they are the smae as the tr6. i will put them in this morning.

 

I have always heard and am pretty sure that 104s are only one step colder than stock. I think the Autolite 103s are two steps colder than stock. I use 104s for a 100-shot (and occasional 150-shot).

 

no worry, my friend had 3 sets of tr6's, so he gave me a set. i will wait till somebody in my club needs the 104's for a 100 shot or so and will give them away.