What spark plug is my best bet to run on a near stock LT1 with a supercharger making around 9psi? Autolite 103 or 104s? ngk tr6? any opinions on guys who have done this? Also opinions on changing the stock plug wires?

 

Its not gonna last on 9PSI very long.

You want to go a step or two colder on the plug selection from stock.

And you REALLY, should consider pulleying that thing down to 7ish PSI if its the stock bottom end and you want it to last for any amount of time.

 

pmed you back for a little more information, thanks -Matt

 

I'm using the stock heat range Autolites. 105 I think. I had trouble with the 103's getting carboned up during daily driving on my low compression 355. With your setup I would go with the 104's and gap them at .030. Can't help you with the wires as I have a radiator mounted Delteq. No matter what wires you get you can plan on spending all day to change those plugs and wires assuming you have the stock exhaust manifolds. With my longtubes and Delteq it can be done in less than an hour.

 

Either 104s or NGK Tr6s

 

If you have a socket like this, it will save you a lot of time

Socket

 

thanks for the help, I will look into a better socket to get teh plugs out! Probably will end up with the autolite 104's gapped at .35, at least I am leaning that way as of now

 

Has anyone used the Mac tools plug socket? I just bought the 5/8 and 13/16 cutaway plug socket off my Mac guy. He said that a few of the f-body shops are using them and like them too.

 

Try the ZEX plug. Works good with high energy ignitions on my FI application. (383 - D1)

 

I like my ngk tr6's.

 

I would go with the 103's. With a near stock motor and
9psi you don't need any additional hot-spots(plugs)causing
detonation.

93z,383,Vortech,NOS,water/methanol

 

The autolites smoked like a freight train and ran like doodie in my car, switched to TR6s and it was like a new car. Idle cleaned up smoke went away, ran smoother. My car will never see anything but the NGKs again.

 

TR6 here...had 104s and 103s and didnt like em..