oem spark plugs?

[farmertan]

i bought these at a swap meet couple yrs ago,the back of big box is dated 73 the small spark plug box is dated 72 does anyone know if these were the original plugs for a 73 340,im not going to build a 100 point trailer queen i just thought it would be neat to have in a car for 100% all original. ive got two of these unopened.

[MEK-Dangerfield]

I can't help you, but that is an amazing find!!     



   Mike

[Chryco Psycho]

I have no source to reference the part # but unwrap one & it should be obvious , they will be a Champion plug & look like a RN12YC

[farmertan]

thanks js29 i looked in my origianl operators manual it says 65p for 318 or 340 n-13y for 318 n-12y for 340, so whats  the dif, heat range? wow it says to replace plugs every 18k miles,nowadays people never replace them.

[Chryco Psycho]

yes heat range ,13 should be slightly cooler