Are there any? How do they perform?

 

Yes, there are alternatives. I use Autolite 103's, no problems at all. Been using them for almost a year now.

 

i have used AC Delco R42LTS plugs for about 8 years pretty much exclusively with no issues... including my current Z06. when i owned my shop i put them in every car that was, HC, N20, FI.. up to the 750rwhp 383 LT4 TA we built before we put the special order Champions (RC59YC i think were the numbers) which are VERY cold but in lots of boost and N20 they work great.. not so much for a street car... of which we did not see any more HP out of them but they did get rid of the Knock we were seeing.

they are the coldest AC delco makes for street use.

its to each his own when it comes to plugs.

 

Is that AC Delco plug colder than the TR-6?

 

Does anybody know if NGK makes a V-Power plug two steps colder than a TR6? NGK told me that running race plugs(non resistor type) will cause electro magnetic interference and possibly damage the PCM. Is this true? Any body running The V-Power Racing plugs(plug numbers that start with an "R") in a daily driven type street car?

 

ttt...

 

I ran Tr7's everyday on the street. I know that they are a "gasket" type plug. But they work. they also make 8's,9', and 10's. Just be careful and make sure the gasket is seated and they will do fine.