Currently running a Champion RS9YC that is 2 steps colder than stock and want to stay somewhere around this heat range.

The question is: is a plug made with a terminal end that is shorter in length than this Champion?

The reason is my shorty headers are burning up the boot specifically on cylinder 5. I do have heat protecting sleeves on them but the boot is a 1/4" from touching w/o heat protection. Shorter the terminal, farther away from the header.

Any ideas?

 

idk how big those champions are, check NGKs and search for the same heat range. can also check autolites

 

Search for lt1 short sparkplug see if that helps. A coulple years ago I went from using ngks to using autolite and have been okay since. The ngks were 1/4" longer on the terminal end. I don't know if the autolites are are shorter than the champion plugs you are using or if you really care to run autolite plugs. I bet it is worth a look. Accell makes a shorty plug also.

 

Long tubes...