48-49 254cid Iron head spark plugs

[Deleted User]

What is a good plug to replace the factory J9 with as J series is hard to find ,with todays fuel is the NGK B6S a good choice? From what I can find out the J9 had a heat range 6 and the J7 heat range 8 Thanks

Uncle Josh

I've been running H10-C with good results in all my Hudsons. 212, 262, 308 and 254

jjbubaboy

Ok with all this plug discussion, I am now wondering what would be the best plug to put in my 36 T with the 212?

Who makes an H 10?

I am using the recommended stock Champions. ( J8 i think)

Thanks,

T Jeff

[Deleted User]

41truck wrote:

What is a good plug to replace the factory J9 with as J series is hard to find ,with todays fuel is the NGK B6S a good choice? From what I can find out the J9 had a heat range 6 and the J7 heat range 8 Thanks

I always used to run Champion J-7 plugs in my Hudson eights, and you are right that they are hard to come by. I believe Hudson recommended the J-7's in the stepdown eights, at least that is what I see in the owner's manual. In my 1950 Commodore 8, I currently have AC 44's which are the comparable heat range of the J-7's. That car runs beautifully with those plugs. I imagine the AC 45's would do fine in the eights as well, for that plug is only slightly hotter. In my 1951 Commodore 8, I have AC 47's, and that car starts and runs fine as well. However, that heat range might be a little too hot for extended summer driving. It makes for easy starting, though. Back when I had cars with the 212 engine, I used Champion J-7's and J-8's, as I recall. The AC 44's and 45's correspond. Although I have not used them, Autolite should have plugs which correspond. Perhaps you can find an old cross reference chart for all these manufacturers.

Uncle Josh

The H 10C is a Champion plug. Basiclly a lawnmower plug. The H 10 is no longer available

[Deleted User]

Thanks to all for the info. Would a champion RH12 plug be to hot for the 254?