[Jtsorey]

I am looking for a high heat range plug around 10. Does anyone have a part number. Part store clerks have no clue when it comes to manually looking up things. And I'm tired of buying plugs and changing them because the motor is in a 82 Camaro

 

[BogiesAnnex1]

Original heads or aftermarket? This hits the needed screw length which is more important than heat range. Also, need to know whether the heads use the post 1970 small hex, taper seat plugs or the older large hex gasketed plugs?

Bogie

 

[Jtsorey]

stock 71 heads tapered seats

 

[johnsongrass1]

AC Delco R45 is the factory. 46 and up is hotter, lower numbers are colder.
What's happening you needing a hot plug? Worn out engine?

 

[BogiesAnnex1]

Why the need to change the heat range. Are they fouling or causing detonation?

Fouling can indicate compression is down, mixture too rich, oil pulling over for a list of reasons from bad rings, valve guides and their seals, lost cam lobes and lifters, poor PCV valve, engine running too cold, or trips too short in cold weather.

The fact a 400 is grafted into a Camaro is not by itself a problem for spark plugs, the big pain here is getting header clearance if they are used with factory insulator length plugs.

Bogie

 

[scotty57406]

i had a problem with the plugs fouling on my 400 sbc, i listened to to many people that the 400s had a over heating problem
so i ran a 165 stat in it, the plugs kept fouling, finally i smartened up and listened to the guys on here that a street engine should not be run that cold, i put a 180 stat in it and the plugs began to clean up, i put 195 in it and they became about as best as you can get, i have a maxi cool rad and a good clutch fan and shroud and the temp always stays below 200*, if you can post a few pics of the fouled plugs i am sure the guys on here will be able to tell you where you need go to fix the problem, Scotty