Spark Plugs

BigSky

Can someone tell me what plugs are a good replacement for the champion J8 plugs? Also, what was the difference between the J8 & the H8 for my 37 Hudson 6 cyl? I'd read or heard rumors that the H8 was a longer plug (used in the aluminum head) perhaps to bump the compression. Which would be an interesting way to get a bump in compression for my cast iron headed 6 Cyl. Anyway, I'm coming up with different options but would love your help!

BigSky

Ops, super power dome head took H10 champion plugs & regular head was J8. Anyone on suggestions?

Geoff

J8's are superseded by J8C, which is the same plug except with a copper core.

BigSky

Thanks Geoff, I picked up some today!