Plug Gap ?

[rellis1962]

First off let me say, I know that I am probably not gaining anything by using the AC rapidfire #8 plug in place of AC MR43LTS plugs. I got the rapidfires because I was unable to find original replacements at the time I was looking for tune-up parts. I have now found an auto parts store that has the original AC plugs. I would still like to use the rapidfires if they are know to work without issues. Also, the preset gap on the rapidfires is less than the original AC plugs. What should the gap be on the rapidfire plugs. Engine is 1999 5.7L carbed Thunderbolt V. I would appreciate any input.
Thanks,
Rob

 

[havasuboatman]

Re: Plug Gap ?

If you are gonna' use them, use the factory set gap on the plugs as long as they are a direct crossover part number.
Betcha' a dollar there is no performance difference at all.

 

[rellis1962]

Re: Plug Gap ?

Yea, I wasn't looking for performance increase. Just plugs for the tune-up and that is what I could find at the time. If there is a good reason to use the original AC MR43LTS replacements, I will. Don't want to cause problems with the motor.

 

[havasuboatman]

Re: Plug Gap ?

I don't see it causing a problem, For me, it's just a personal thing, I work on other peoples boats. Most of them figuer if I put a spark plug in that has a different part number, even though it's exactly the same plug, just a different manufacturer, I used the wrong plug.
I actually had to go to court to explain that it was the four lbs of sand the owner sucked into his motor, not the fact that I used AC plugs (or whatever they were) instead of NGK plugs, that casued his engine to over heat and his heads to crack.
So, when the sticker says use Ngk, I do.