I have a 1989 IROC-Z carbureted engine with aluminum heads. It has one of the original ZZZ 350 crate engines (bottom of page 6). The block is the same as the OEM engine. The internal parts (rods) crank up-beat which makes this car stout and fast.
It is time to replace the spark plugs. I understand iridium may be too hot for the aluminum heads.
I am considering the AC Delco 19307140 (aka the 41-808) and the 19301809 (aka the 41-905). I am leaning toward the 41-905 plug.
- 41-808 gap = .047"
41-808 reach = .75"
41-905 gap = .035"
- 41-905 reach = .43"
Would the AC Delco 41-905 sparkplug work well in my engine?