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help with spark plug selection

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Old 07-26-2018 | 06:24 AM
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Default help with spark plug selection

Sounds easy enough...but I'm looking for a good starting point for spark plugs on my new motor...it was previously a 525 sc and I ran MR43t's and never had an issue...new engine is as follows..

460 with eagle rods, JE blower pistons, 8.2:1 CR
Dart iron eagle heads
MSD marine box coil and dist
Dyers 8-71 blower 5-6 lbs of boost is what I'm expecting
always run 93 octane gas

Just looking for a good starting point for plugs so I don't burn this thing down lol

According to darts website I believe the heads take a gasket seal type plug but I forgot to confirm that last night while I was working on the boat

Thanks!!

Stewart
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Old 07-26-2018 | 08:22 AM
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AR3934 autolite

NGK 5671A-8
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Old 07-26-2018 | 08:29 AM
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Thanks MT...so its my understanding that if I have fouling issues the 5671A-7 would be a touch hotter is that correct??
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Old 07-26-2018 | 08:31 AM
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Also what's your advice on gap for them??
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Old 07-27-2018 | 06:50 PM
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Yes, the -7 would be hotter. If youre fouling -8 plugs, youre probably extremely rich at idle.

i gap mine to .035
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Old 07-27-2018 | 08:34 PM
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To go along with MT said.

http://dartheads.com/wp-content/uplo...tion-Sheet.pdf
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Old 07-28-2018 | 05:03 AM
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Awesome..thanks for the info guys!!
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