I am installing a Procharger D1SC onto my 383 that will be running around 10-12 lbs of boost. AFR suggests normally running fr3ls plugs in them as a start but says to go 1 to 2 heat ranges colder for a blower motor. Would I be better off with the FR2LS or FR1LS plugs? Anybody have any experience with these?

 

In for pics.

 

I use autolite 3923 on my engine

 

 

Whatever brand you use, find what heat range is stock. Built motor high comp, usually step down 1-2. Mild nitrous or mild boost, step down 1 more. Heavy nitrous or boost, step down 1-2 more.

I use ngk. 4-5 heat range is stock. Built na motor you run 6's. mild boost 7's. my heavy booster i run 8's

 

double check with the plug manf. some plug numbers that go low don't mean it's a colder plug but usually start with 2 colder and if the engine doesn't like it step up to the hotter plug

 

I've been running e3's e3.48 but I can't figure out if this is good plug for a procharged engine . Has anyone found a heat rating for these or had good luck running them supercharged?

 

another one for the autolite 3923's and there cheap at $1.80 a plug