I've been google'ing and even looked up the part number on rockauto, but I'm confused. the local autoparts store gave me Bosch Platinum HR9BP (installed now), my service manual says AC R46TS and rockauto lists AC Delco R43TS. what's the right one? all of the heat ranges are different. I ask because when I rev my engine and under hard accelleration the engine pops out of the exhaust rediculously, sometimes when I accelerate WOT it will reach a certain RPM and pop so much it hardly accelerates for a second then will pick back up. For the first 2 minutes that the engine starts up, it revs up fine. Idle is fine, but the idle hunts when it's warming up.

Sounds like you need to adjust your timing a bit...

As far as spark plugs go all I know are Delcos cuz thats all I use and both the R46TS and R43TS is correct for the L98 but the heat range isnt important enough to cause backfiring unless you are way off so I would look into your timing. I use R42TS in my car because I have higher compression. the R46TS in your service manual is because they wanted the motor to burn hotter to help emmisions but R43TS is the common replacement plug.

hope this helps

Take what you have in there and throw them away....I'm running R43TS with 10 to 1 compression, ac delco all the way. Unfortunatly like above said, your backfiring problem is probly not the plugs. Check timing and injectors...

i have always done best with NGK TR-6 or TR55's plugs

I run acdelco r44ts in one of my birds and acdelco 41-6something in my "toy".

AC Delco all the way.