Does anyone know what size socket fits the 396 spark plugs? I am trying to remove the plugs on my 1970 El Camino SS 396 but none of my spark plug sockets seem to fit. They just spin and don't grab the plug. Not sure if it's because they are too big or because there isn't enough clearance. Do I need to invest in a thin wall socket? If so, need to know what size to get.

Thanks for reading.

Mike

 

It would be a 13/16"

 

Ok thank you. Appreciate it.

 

Update:

On a whim, I tried my 5/8 plug socket and it fit perfectly. Took me almost two hours of struggle to finally get the rear plugs on each side replaced. They sure don't give you much room. So now I am wondering if the heads on this engine are original or were replaced at some point. Research indicates Chevy started using 5/8's plugs in the early 70's so maybe they are original heads after all. One of the problems when you buy a used muscle car is that you don't know what was done to it...

 

1970 original would have been 13/16 plug base.