spark plug info

I currently run a 540 BBC, conventional heads and 12.4:1 compression, 8-71 HELIX Kobelco
i have NGK 5671A-9 plugs (pretty sure of the number).
what plugs do you reccomend and what is the difference in the -10 vs the -9. I have seen several people running the -10's and was wondering what the advantages or disadvantages were

 

the -10 is one step colder. How are your -9's reading? I run -9 plugs in my blown alky SBC. I don't lean on it real hard, however. I've ran -8s also, but get better plug reads with -9. You can also run B9es plugs.

 

3-D
I run extremely close motors to what you described.
I use the same plug, yes -9's. I plan to try some -10's later this season. My understanding is this really only changes the temperature of the porcelain or how fast the porcelain can get rid of the heat. So I'm not expecting any plug reading or performance difference.

I tractor pull and was in your area last weekend, I was in Taylor and Whitewright. 106 degrees sure makes parts hot to the touch, I'm sure glad there wasn't our humidity to go with it.