[BillsCamino]

Looking for a spark plug recommendation to use in GM -702 closed chamber heads. Mild performance build...10.2 CR with Comp hyd flat cam, headers, intake, carb. Heads have 2.19/1.88 stainless valves and port/chamber work.
These heads take the old style 13/16" steel sealing ring type plug...

 

[von]

I'd use AC R44S. That's an extended tip mid heat range resistor plug.

 

[mr 4 speed]

I think I have Autolite 66 plugs in my 063 heads.
Used to use AC R43XLS

 

[BillsCamino]

:thumbsup:
I've got a set of AC R44XLS which I started to use but it didn't seem like they thread in very far.
Just checking here to make sure I'm using the right style plug.

Been a long time since I've installed a set of these lawn mower spark plugs.
Surprised that I still had a socket...

 

[chvyscott67]

do they make an NGK plug for those heads, i too have a set of 702's to put in place of the 292's once they're out of the shop, an the NGK's are whats in the 292's an seem to work very well !

 

[CDN SS]

:thumbsup:
I've got a set of AC R44XLS which I started to use but it didn't seem like they thread in very far.
Just checking here to make sure I'm using the right style plug.

Been a long time since I've installed a set of these lawn mower spark plugs.
Surprised that I still had a socket...

Hey Bill yep thats the right plug for those 702's :thumbsup: dont be tempted to go colder like 43's for a street cruiser the 44 is hard to beat and the XLS is the right reach plug

 

[greg_moreira]

r43XLS is what I used to use on my 215 ovals. Went to the R44.

With a DP carb....I had occasional fouling in cooler weather with extended idling. The 44's give me less fits.