Looking for recommondations from those of you that have run Victor heads on a race only big block. Has 13to1 compession, with small dome and roller cam. Am interested mostly n/a at this time but also for use with up to 200 horse of spray, MAX.What are your experiences? Thanks in advance Bill

I like and use Autolite racing plugs in my motors that use the 5/8 plug socket size with the 3/4 inch reach like the Victors need, on your deal on straight gasoline with no spray I would try their 3911, on spray the next step colder 3910 If you have piston to plug clearance issues try the 3932 or maybe the 3931
I race my S/P car on pump E85 with 15.0 to 1 compression and it likes the retracted gap Autolite 3934. E85 is weird, it does not like cold plugs

Cab...Have you ever tried NGK?

I have used them in, NGK, the past on iron headed and aluminum headed bracket race motors, I've also used Champion, Motorcraft, AC and several other brands that I can't think of now

I used Champion C59CX in my 514 race engine when it was 13.5 compression. The Champion race plugs always worked well for me. They have a cut back ground strap so they are really sturdy.

I use an Autolite 3923 on the street and an NGK 7 on the track. 12.5:1 511. I think i could go 1 range hotter on street.

I use the NGK 8 heat range in the 500" 12.4:1 Victor MW head engine. .

On the mild street 505" 10.3:1 Stealth head engine, The 8's were too cold, so went with 6's.

I think the Code is BKR8E (8 = heat range, so change # lower for a hotter plug, or increase # for a colder plug.) if there is a letter after, indicates different tip style, like P for Platinum tip, or I for iridium tip. the last part is a -# (dash number) that is the pre-set spark plug gap in mm/10. example: -10 = 1.0mm or 0.040" gap.
The "code" is not the stocking part number.

Heck, just found the old thread here:
https://board.moparts.org/ubbthread...16/ngk-spark-plug-for-stealth-heads.html

Old link to chart is broken, found another link with the plug chart here:
https://www.lsengineers.co.uk/blog/guide-for-ngk-spark-plug-numbering-system.html

Thanks for the link, 451,
Now in my "book'

Joe

same here, in my book as well. a BIG thanks !