Correct spark plug gap

[Smoothwater]

I'm replacing the AC Delco's with the NGK TR5 and am a little confused on the right gap for them. What would be the gap for a 2001 Indmar 350 with the carb. I thought it was .030 but I got information through Skidim that they are gapping at .045 so not real sure.

[MJHSupra]

The 5.7 Pre Vortex is 0.035. MR43T
The 5.7 Vortex Carb is 0.03. MR43LTS

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[MJHSupra]

Those numbers came from an Indmar Spark Plug Chart.
I did a screen capture b/c forget it.
Probably can Google the same thing.

It also lists the plug wires #s.

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[Smoothwater]

Thanks. It is a Vortec. I pulled a couple of plugs to check and they were gapped about .045. Has always run well though. Guess I'll do the new ones at .030.

[larry_arizona]

Plugs wear, especially the copper plugs you are referencing. Measuring used plugs is not an accurate indicator of what the gap should be.


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[Shawn Mendes]

Here you can find an interesting article about top 5 spark plugs for Vortec:

https://autokwix.com/review/best-spark-plugs-for-vortec/

[VA LSV]

According to NGK the correct gap is 0.040".

http://partcat.com/ngk