shorty spark plugs

[coltdaddy47]

83 gmc 350 .60 over, rv cam, intake, 600 edelbrock, summit headers. I need some shorty spark plugs for these headers and everything I keep researching is confusing. I have no idea which plugs I should go for. What "specs" should I look for. What brand, heat range. Part number lol? Any info would be appreciated.

 

[bucket]

I've used Accel 476S in similar applications. Pretty sure at least, haven't used them in a while, but that number seems correct.

Hope that helps.

 

[coltdaddy47]

I came across the 576s. I just don't know what I need to look for. Don't even know what the difference is for them. If anybody confess across a good learning page I'd be interested.

 

[rich weyand]

You probably want to use the ACDelco R45TS. R is resistor, 45 is the heat range, T is the shape/size of the flange, and S is for short. Most commonly GM-recommended plug for our era 350s in lots of flavors.

Generally speaking, you want to use the coldest plug that doesn't foul. "Hot" and "Cold" here do not relate to performance, but to temperature. The amount of contact between the plug body and the ceramic inner determines how hot the plug will run. Less contact and it will be hotter, more contact and it will be cooler because the heat of the core will be conducted to the block better.

Cooler is better because it is less prone to pre-ignition/detonation/knocking. But too cool and the plug won't burn off carbon/soot and the plug will foul. Like I say, most 350s from our era run well on the AS Delco R45TS. You can also run the Autolite 24, which is a little cooler than the ACD R45TS, but that's OK because they are less prone to fouling. All the dirt-track racers around here use the Autolite 24s in SBCs.

http://www.78ta.com/HTAF/index.php?topic=6782.0

 

[coltdaddy47]

Thanks rich, I'll check into those.