Sorry if this is obvious or easy, I've never built an engine before...

I'm going to be installing my 383 stroker soon, not sure how to choose the proper plugs. Do I just go with the ones the 350 for the same year calls for? I've read some posts that recommend shorter plugs when running headers (as I am), but other than that I'm a bit lost as where to start.

If it matters, this will be a 383 with the HSR, approximately 400 HP. Thanks.

 

Spark plugs depend upon the heads. You go up or down in heat range based on how it does when you get it running and use it like you intend to use it.

 

Okay, that makes sense...suggestion for a good starting point? This is not a daily driver, more of a weekend warrior or nighttime cruiser. Not planning on taking it to the strip or anything.

 

As five7kid says, match the plug to the head. If your running a vortec style head make sure you get the right plugs for the head. When i used a set of GM vortec heads on one of my older cars, they needed plugs that are longer than your standard GM plug (R44ts). The standard plug sat maybe an 1/8 of an inch inside the head when you looked at the combustion chamber.

 

They are Edelbrock Performer RPM heads; on their website, they recommend Champion RC12YC plugs. Seems like a good place to start.

 

you cant beat good ol AC plugs,i think they make shorties for header use too. the thing to remember is this;as the compression rto goes up,the heat range of the plugs goes down. r-44s work well till you go over ,say 9.5-1 then its r-43s for you and so on

 

My god.. cross that number with AC delco or NGK even a ford plug..
NO champions unless u have a lawn mower..

I use FR3LS or FR5LS mostly.. that maybe older delco numbers.

 

No Champion plugs. Got it. What is the best (or a good) plug to get? Not worried about cost, just want something good.

 

Nothing wrong with Champions. They're just yerbasic stock plug. Racers have been using em for years by preference because the steps between heat ranges are smaller in that brand than in others.

R12YC crosses to about a R45TS in AC Delco. Equally basic. Which that # I believe is the stock one for most of these cars anyway... meaning, look up the stock plugs for your year with a 305 in whatever brand you choose, and what you get will be the right thread, heat range, etc.

Any of the OEM grade plug mfrs will work fine. AC Delco, Champion, NGK, ND, Bosch or Motorcraft. Avoid any kind of "gimmick" plugs; for example, the regular stock Bosch equivalent to the R45TS, NOT the "+4" or any of that. No "Splitfire", no "Ewhatever", none of that wallet-draining monkey-spank. Just, yerbasic stock replacement. No sense spending extra money just to shoot yourself in the shorts with a bunch of marketing hype that will only cause you problems.

Rest assured that among all the variables affecting engine performance, spark plug choice is WAY down low on the list. As long as they FIT and WORK, that's about 95% of the battle.

 

Great. Thanks for the good info.

 

My cuz worked at Champion several years ago in the R&D department. He told me many storys about how 1 in 4 plugs were "good"..
Use the info how you want.