Spark Plugs for my 400ci Charger?

Ian Deady · Post by **Ian Deady** » Mon Dec 28, 15 8:06 pm

I know a lot of ground was covered in the 440 Spark Plug sticky, so I apologise in advance. In my defence, I'm a noob, and have a car that I haven't got to drive yet. 73 Charger with I think a B series, 400ci from a 72.
Has a eddlebrook 600cfm, performer intake and may be a "magnum" block?
I guess it'll probably be approx 260hp. Currently has autolite 86 plugs, (small, short threads). What NGK's can I use?

Many thanks.👌

John · Post by **John** » Mon Dec 28, 15 8:16 pm

Are they Stock cast or Ally Heads Ian?

Stock cast have the larger diameter and Ally have the smaller type

John · Post by **John** » Mon Dec 28, 15 8:23 pm

I use NGK BPR6ES For the stock heads and NGK BKR6E for Ally heads. Both have the longer thread length however

Scooby · Post by **Scooby** » Mon Dec 28, 15 8:59 pm

I know guys on here like there nkgs but I use auto lite on my 408 stroker ...
Magnum heads ...

68Runner · Post by **68Runner** » Tue Dec 29, 15 11:07 am

On a standard 383 the plugs are NGK BP5S or Champion RJ12YC