Curious,

I'm using 104's right now and the car is breaking up at 4-4400rpm.. which is where peak torque occurs so i have an idea that the spark is being blown out.


What gap also?

 

I have never had even remotely good luck with autolites, but if I had to run them on that engine I’d be running 103 or whatever cross-references to the same plug as a 103 but non resistor. The problem with autolite resistor plugs is that they have very brittle ceramic which tends to lead to cracked plugs and a questionable manufacturing process that tends to end up with loose center electrodes (I’ve seen 5 of 8 NEW autolites come out of the box with loose center electrodes, and I’ve seen whole sets come out of cars that way). The non resistor plugs don’t seem to do that.

If it was my car I’d try NGK TR6’s gapped to about .032-.036”, though I’ve seen cars that needed as little as .024” to reliably fire the mixture under boost.

Are you running any aftermarket ignition goodies/ignition boxes?

 

....the car is breaking up at 4-4400rpm..

Sounds like typical symptom of the stock ignition when boost is applied. Is it?

 

nope.. its got all msd stuff