Question on spark plugs and header bolts.

Jims442

Greasemonkey
Dec 2, 2019
149
28
Connecticut
Good morning all. I have a few questions to ask. I'm running a 350 bored to a 355 with a weiand 144 blower 950 holley holley 4 bolt heads and headers. First question is I'm running autolite 3923 plugs and so far all the one I'm able to remove are burning fine. Just old. What is the difference between a hot or cold plug and what would these be considered ? Next question is. How do you get the plug out if you can't get a socket on it, because the headers are in the way? And last question. How do you get to the back bolts on the headers to tighten them? I have 2 loose header bolts and I got a 7/16 wrench on one but the other is buried in the on the right side. Also to me a wrench doesn't seem like the proper tool to do the job either way???? PS The reason I'm pulling the plugs is because I think I'm getting a misfire when she warms up. But I'm having trouble deciphering if it's the lobe from the cam or the plugs. Ty Jim
 

pontiacgp

blank
Mar 31, 2006
29,389
113
Kitchener, Ontario
for the misfire put the plugs back in, start the engoine and use a laser temp gun on the headers to see which tube(s) is cooler than the rest, that is the easiest way I know of to see which cylinder(s) is not firing. ....to get to the header bolts removing the wheel and going though the wheel well is usually easier
 

GuysMonteSS

Royal Smart Person
May 21, 2011
1,449
113
Kentville,Nova Scotia,Canada
Sometimes you have to make,modify or buy special tools for plug removal with headers.
With my 468 BBC I had to cut,grind and bend a wrench to get at a couple of plugs.
Now my 513 has raised exhaust port AFR heads.My buddy threw a spark plug socket in the lathe and both ends have been shortened to access 2 or 3 plugs.
You might be able to get to the back header bolts from underneath,or jack the front up,take the front wheels off and see if you can reach them that way.
Guy
 

Jims442

Greasemonkey
Thread starter
Dec 2, 2019
149
28
Connecticut
for the misfire put the plugs back in, start the engoine and use a laser temp gun on the headers to see which tube(s) is cooler than the rest, that is the easiest way I know of to see which cylinder(s) is not firing. ....to get to the header bolts removing the wheel and going though the wheel well is usually easier
Ty
 

Jims442

Greasemonkey
Thread starter
Dec 2, 2019
149
28
Connecticut
Sometimes you have to make,modify or buy special tools for plug removal with headers.
With my 468 BBC I had to cut,grind and bend a wrench to get at a couple of plugs.
Now my 513 has raised exhaust port AFR heads.My buddy threw a spark plug socket in the lathe and both ends have been shortened to access 2 or 3 plugs.
You might be able to get to the back header bolts from underneath,or jack the front up,take the front wheels off and see if you can reach them that way.
Guy
Ty
 
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Jims442

Greasemonkey
Thread starter
Dec 2, 2019
149
28
Connecticut
if you can get a plug socket on it you can use a 3/4" wrench on the socket. It usually only takes a half turn to break the torque and then I use a 3/8" vaccum hose to slide onto the plug to turn it out to remove it. The hose helps to install the plug as well
TY
 
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fleming442

Captain Tenneal
Supporting Member
Dec 26, 2013
13,085
113

Jims442

Greasemonkey
Thread starter
Dec 2, 2019
149
28
Connecticut

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