Picking spark plugs for 383 stroker
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Picking spark plugs for 383 stroker
Going to order spark plugs for my 383 stroker soon and I’ve got AFR heads on it, they recommend either Autolite 3924, or ac delco 41629. I’m not putting lawn mower spark plugs in my car and AC delco doesn’t use that part number anymore and the only cross reference I can find is for their conventional spark plugs. I want to run either AC delco or NGK but just need help determining which to order. This will be an NA street car, hopefully making around the 400-450 whp mark so I want to make sure I get good quality plugs for it. Let me know what you guys are running if they’ve worked good for you or whatever recommendations you’ve got.
Le Mans Master
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I run a delco 41-627 on my car. Iirc it crosses to a NGK BKR5E-11. That 41-629 is however still a valid part number as I was going to use them as well. I believe they are colder but only slightly. Same reach just a different heat range.
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for whatever reason summit told me that part number wasn’t used anymore and they told me it cross referenced with some other plug that’s just a regular conventional delco plug so I guess I’ll try and find them elsewhere. Are you happy with the 41-627 or do you think it would be better to go with the 629? Or would it be better to go with NGK instead? Every GM I’ve owned I’ve always gone with delco plugs but just about anything else I use NGK for so not sure what I want to do this time.
Le Mans Master
Joined: Aug 2017
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From: New Jersey
for whatever reason summit told me that part number wasn’t used anymore and they told me it cross referenced with some other plug that’s just a regular conventional delco plug so I guess I’ll try and find them elsewhere. Are you happy with the 41-627 or do you think it would be better to go with the 629? Or would it be better to go with NGK instead? Every GM I’ve owned I’ve always gone with delco plugs but just about anything else I use NGK for so not sure what I want to do this time.
Last edited by 84 4+3; Apr 22, 2021 at 10:29 PM.
Safety Car
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From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
I run Autolite 3924 plugs, gapped @ .045" with AFR 195 heads and DUI dizzy with no issues and still run mid 12s with a CFI motor. They work just fine for me. 
EDIT: I must have the BEST 383 lawnmower engine around.
EDIT: I must have the BEST 383 lawnmower engine around.
Last edited by Buccaneer; Apr 23, 2021 at 12:51 PM.
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