Simple spark plug question...

[TomAce82]

Is there a plug that uses a 5/8 socket with the same characteristics of a stock 13/16 head plug? I have header clearance problems on my 383 Belvedere. Thanks!

 

[Moparstyle]

You should be able to cross reference them what ever brand plug your running just make sure the plug depth heat range is the same take a plug in where ever you go to match it up you just need a real parts guy not a autozone computer jockey lol good luck

 

[91r/t]

Should be able to take whatever plug you are using and cross reference it to a smaller 5/8 plug. I had to do the same to my 360 for my Power Wagon when I used the Magnum heads. They use the smaller plug holes and needed the smaller plugs.

 

[TomAce82]

Thank you both. To clarify, I have stock heads with stock plug holes. Just looking for a part number that I can put right in. For example, Autolite 85 but with a 5/8 head size. I understand I need the same plug depth and heat range, I’m looking for the plug part number that someone has ran under these circumstances (header clearance, can’t get socket on 13/16” plug) I’m reaching out to the guru’s vs. the parts kids. Anyone had this issue? What plug did you use?

 

[coloradodave]

To the best of my knowledge there are no plugs that fit your heads and use a 5/8" socket. Over the years I have "modified" a 13/16" socket by cutting a window in the side so that the socket could slip sideways on to the plug and then used a 13/16" open end wrench to turn the plug socket. Also, on some heads/headers it's possible to use an offset box wrench on the plugs instead of a socket. The wrenches can be heated and bent to fit , as well. Last resort, remove the headers, heat the pipes where there is interference and use a piece of iron pipe and a hammer to gently put "clearance" where the manufacturer should have. All a part of hot rodding. Good luck!

 

[TomAce82]

To the best of my knowledge there are no plugs that fit your heads and use a 5/8" socket. Over the years I have "modified" a 13/16" socket by cutting a window in the side so that the socket could slip sideways on to the plug and then used a 13/16" open end wrench to turn the plug socket. Also, on some heads/headers it's possible to use an offset box wrench on the plugs instead of a socket. The wrenches can be heated and bent to fit , as well. Last resort, remove the headers, heat the pipes where there is interference and use a piece of iron pipe and a hammer to gently put "clearance" where the manufacturer should have. All a part of hot rodding. Good luck!

Thank you! Helped me to not go in circles at the parts store. I was hoping that wasn’t the answer, but figured it might be. For reference, my headers are the Summit Brand ceramic coated type. Love everything but the plug situation!

 

[91r/t]

I am running an NGK FR5 plug but I believe it has a farther reach then a stock plug. It is what is needed with the Magnum style heads I am using.

 

[bm02tj]

The smaller plugs are mostly taper seat and the larger one seal on a gasket

 

[WileERobby]

As Dave says, you're not restricted to a socket. I've used open end, box end, offset, custom homemade bent wrenches, homemade cut sockets... whatever it takes to remove or install for a snug fit. Gorilla torque is not necessary.