Spark Plugs in a modified 258?
Von
Jeeper
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- 1979 CJ7 Rebuild Project, 258 Aluminum Intake, 4 bbl Holley, Split Headers, Dual Exaust, T-150.
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Spark Plugs in a modified 258?
- Thread starter Von
- Start date
Torxhead
Always Off-Roading Jeeper
I would go for the 985s, then check the deposits on the spark plugs, and adjust the carb jets until a good air/fuel mixture shows on the plugs. That Holley four holer is a bit on the big side in my opinion.
Von
Jeeper
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- Broadalbin, New York
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- 1979 CJ7 Rebuild Project, 258 Aluminum Intake, 4 bbl Holley, Split Headers, Dual Exaust, T-150.
Thanks Torxhead, I think I will do that. Yes! I think that the 4 holer is a bit much too! I just bought it last month and it's a project jeep so that set up will probably change down the road! Thanks again!
CJim7
Crazy Sr. Respected Jeeper
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- '84 CJ7 - 430hp 401 on propane - T18a/D300 twinsticked, Superior axles, Lockers, full boatsides, Warn 8274, OBA, 36" TSL's.
I've used the 985's for years in my heavily modified AMC 258 i6 / 4.2l as well as my 401 without any issues. I've never had any desire to use the splitfires or the platinums or any other snake oil plugs. The key is proper gapping, timing, and fuel mixture for the application...
Von
Jeeper
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- Broadalbin, New York
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- 1979 CJ7 Rebuild Project, 258 Aluminum Intake, 4 bbl Holley, Split Headers, Dual Exaust, T-150.
Thanks CJim7! I did put the 985's in and gapped them at .35. After the plug install I notice it's running like on high idol now? I'm trying to find someone local who can come take a look at the Holley and check the timing. This jeep has been sitting for quite some time before I bought it.