Shorty spark plugs for my Blue Print 383.

lucky 1985

Not-quite-so-new-guy
May 5, 2016
34
8
The recommended plugs in my Blue Print 383 are too long for the cast headers I have. I don't want to change headers, so I am looking for a short plug replacement for NGK 7938 BKR5E. Thanks for any ideas.
 

melloelky

Comic Book Super Hero
Oct 22, 2017
3,786
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mass
The recommended plugs in my Blue Print 383 are too long for the cast headers I have. I don't want to change headers, so I am looking for a short plug replacement for NGK 7938 BKR5E. Thanks for any ideas.
I've used the accel short plugs and the auto lite 133's with good luck.those are a tapered plug,yours is a gasket'd style.I'm sure you'll find something from those plug companies in the gasket'd form.fyi the plug heat range you have now is 5.
 
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lucky 1985

Not-quite-so-new-guy
Thread starter
May 5, 2016
34
8
I'll take a look at the Accel and Autolite plugs.

And to add to my knowledge about plugs, tapered and gasketed refers to the thread style, right? Tapered being, well, tapered, and gasketed being straight threads with a crush ring.

I appreciate the help, I am learning as I go.
 

melloelky

Comic Book Super Hero
Oct 22, 2017
3,786
113
mass
I'll take a look at the Accel and Autolite plugs.

And to add to my knowledge about plugs, tapered and gasketed refers to the thread style, right? Tapered being, well, tapered, and gasketed being straight threads with a crush ring.

I appreciate the help, I am learning as I go.
yes and no-gasket-tapered refers to the plug style more than the threaded portion.your spark plug holes are machined flat inside requiring a gasket-crush ring on the plug to make the seal.the tapered plug holes rely on the tapered negitive surface on the spark plug itself to make the seal.another thing to keep in mind you're gonna need a plug that has a .750" of a "reach".that's the lenght of the thread portion itself.anything less and the electrode won't reach the combustion chamber properly.
 
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lucky 1985

Not-quite-so-new-guy
Thread starter
May 5, 2016
34
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Thanks for the clarification on the threads and the threaded portion length. I understand the electrode's gotta sit at a particular depth, that's how it's engineered.
 

565bbchevy

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Aug 8, 2011
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lucky 1985

Not-quite-so-new-guy
Thread starter
May 5, 2016
34
8
Settled for a universal set of plug wires with ceramic boots. Not my first choice but it'll do.
 
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lucky 1985

Not-quite-so-new-guy
Thread starter
May 5, 2016
34
8
What are full length spark plugs interfering with on that style exhaust manifold that you need a shorter version?
The spark plug location on the BP aluminum heads are not in the same location as OEM Chevy heads. My choice of cast headers, which fit well on the heads, physically hit the plug tip on at least 2 cylinders. No way to get a boot on them.

I just tried the smaller ACCEL "shorty" plugs and they are literally the same size as the NGK plugs recommended by BP, so that turned out to be dead end.

I guess I need to make another choice of headers.

Back to square one.
 

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