Is this the right spark plug? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

justin_nelson · 02-24-2011, 12:21 PM

I have a 250 inline 6 and went to local parts store and told them i needed plugs and this is what they gave me. They are the same overall length but the threads are longer than the ones that were in it. they thread all the way in but i just want to make sure they arent going to be hitting anything inside because the threads are longer.
thanks for all your help
justin

and heres a pic of my freshly painted motor

Mike J · 02-24-2011, 12:28 PM

I can't see the pics on the computer here at work- but you don't want the electrode end to be too long- it could possibly come in contact with the piston, and that won't be good. I would make sure that got the part number correct for your application.

**too much stuff** · 02-24-2011, 12:33 PM

I would get the number off the old plug and cross reference or get the same ones. Make sure of the year of the engine and if you are running HEI or not.
Eric

Wrenchbender Ret · 02-24-2011, 01:34 PM

They changed the length of the threads on these engines around 1970 to the shorter plug. Often the older heads were put on a later engine. Check the length in the head. Also the longer plugs had a flat seat & used a gasket.

camrycurt · 02-24-2011, 02:50 PM

Quote:

Originally Posted by too much stuff

I would get the number off the old plug and cross reference or get the same ones.

x2 on the cross-referencing. It took me three tries to get the right plugs for my new truck because the engine is not original and is from some old car, etc., etc.

IIRC, the Autolite website had a really good cross-reference and lookup feature that helped me a lot when I was trying to find the right plugs for my engine.

Good luck! Your engine looks great by the way.

02-24-2011, 12:21 PM	#1
justin_nelson Registered User Join Date: Dec 2010 Location: Brooksville, FL Posts: 35	Is this the right spark plug? I have a 250 inline 6 and went to local parts store and told them i needed plugs and this is what they gave me. They are the same overall length but the threads are longer than the ones that were in it. they thread all the way in but i just want to make sure they arent going to be hitting anything inside because the threads are longer. thanks for all your help justin and heres a pic of my freshly painted motor

02-24-2011, 12:28 PM	#2
Mike J vw guy & now c-10 guy Join Date: Sep 2008 Location: Louisville,KY Posts: 483	Re: Is this the right spark plug? I can't see the pics on the computer here at work- but you don't want the electrode end to be too long- it could possibly come in contact with the piston, and that won't be good. I would make sure that got the part number correct for your application. __________________ '68 long fleet Finally made some progress on the build!!! My Build Thread

02-24-2011, 12:33 PM	#3
too much stuff Roadtrip! Join Date: Feb 2003 Location: Grand Rapids MN Posts: 13,787	Re: Is this the right spark plug? I would get the number off the old plug and cross reference or get the same ones. Make sure of the year of the engine and if you are running HEI or not. Eric __________________ 67 gmc custom lwb dakota truck. Sold...And bought back 69 swb 4x4 project (in progress) 70 c-10 lwb texas truck 70 4x4/BB/bkts/posi/tach(retired) 70 swb (wifes) 70 jimmy camper 71 K-5 factory 2wd 71 cheyenne 4x4/tach/posi/ plow rig 71 Cheyenne20 BB, buckets, tach, tilt, 4 speed 72 jimmy CST wyoming rig 72 jimmy Colorado rig 72 lifted texas 4x4 3/4 ton burb 65 fury conv. 383/auto 65 chrysler 300 "L" 413 auto

02-24-2011, 01:34 PM	#4
Wrenchbender Ret Registered User Join Date: Oct 2005 Location: Overland Park, Ks. Posts: 5,229	Re: Is this the right spark plug? They changed the length of the threads on these engines around 1970 to the shorter plug. Often the older heads were put on a later engine. Check the length in the head. Also the longer plugs had a flat seat & used a gasket.



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