spark plugs

[jcelk]

i have a 350 gm engine made in mexico with 882 heads have autolite 26 in there now they look good i was wondering if the reach was right and what plug is the best thanks

 

[Sweet_Johnny]

The 882 heads were available in two different chamber sizes which will affect plug choice, as will the engine specs. If the Autolites appear to burn correctly then a spark plug cross reference will tell you what interchanges. https://www.sparkplug-crossreference.com/convert/AUTOLITE/26

Some swear by Champion, others NGK, and still others claim good old Autolites are perfect in a mild SBC. I'll be trying some Champion Platinums soon but have typically ran Accel or Bosch.

 

[jcelk]

thanks johnny i didn;t know they had 2 chamber sizes thought they were all 76 cc is there a way to tell the difference ? without a year make and model for this engine maybe i should get plugs for a 1977 350 impala

 

[pagrunt]

To be honest, chamber size really won't do anything towards what plugs needed. Most SBC's from the early '70's ran AC R45TS plugs. Biggest thing would be if you would need a hotter or cooler heat range plug which would be the likes of the AC R43TS, R44TS, R45TS or R46TS. I personally run R45TS or its equivalent. Biggest thing would be would basic, platinum or what every long life plug would be best suited for you needs.

 

[Sweet_Johnny]

To be honest, chamber size really won't do anything towards what plugs needed. Most SBC's from the early '70's ran AC R45TS plugs. Biggest thing would be if you would need a hotter or cooler heat range plug which would be the likes of the AC R43TS, R44TS, R45TS or R46TS. I personally run R45TS or its equivalent. Biggest thing would be would basic, platinum or what every long life plug would be best suited for you needs.

I was just hinting that CR plays a role in plug selection as it influences what heat range is required, as does driving style. You're 100% correct though.

thanks johnny i didn;t know they had 2 chamber sizes thought they were all 76 cc is there a way to tell the difference ? without a year make and model for this engine maybe i should get plugs for a 1977 350 impala

You'll be fine with any of the plugs listed above by pagrunt. Changing by just a range or two is helpful when fighting preignition or dialing in the absolute best performance for the current weather.