carrman
Senior Member
Researching last night led to a post on the Dock by a member here:
Moe, I've written several posts in the past warning people not to try the E-head + C-body HP manifold combo because of #7 plug interference.
You'll save yourself a lot of grief if you get headers. TTI and Schumacher have been recommended by others, but someone posted pics of a mockup of the Hedman shorties on E-heads and they looked promising as well.
If you really want to try to make the HP manifolds work, here's my advice:
Don't bother looking for the Accel shorty plugs. They won't help. They're not much shorter than the recommended Champion plugs and won't move the boot far enough away from the manifold downpipe to make a difference.
I am using a hi-temp tight 90* boot and my #7 plug wire loops up from the back of the engine and along the edge of the valve cover/intake manifold to get to the distributor. (That is the factory wire routing for my 66, I don't know if they changed it for 67.) I also use a Moroso woven ceramic boot protector. These have the highest temp rating available. They are Moroso #71990 but I think they may have been discontinued. (The material was actually developed by 3M and is still available from 3M.) Even with these boot protectors, I still have to replace the #7 plug boot at least once a year.
I'm using a Mopar orange box ignition. If I was using a higher-power ignition system like an MSD, it would probably arc through the boot and protector to the manifold within minutes of startup when at idle. That's what happened when my engine was on the dyno, and they tried fibreglass insulation to protect the boot.
Also, for servicing the #7 plug, I cut-down a regular spark plug socket really short so I could slip it onto the spark plug. I ground a new hex into the outside of the socket so I could turn it with an open-end wrench. A standard spark plug socket will hit the manifold, cock sideways and snap the spark plug insulator more ofthen than not when removing or installing the plug. Obviously, you must jack-up the car and climb underneath to service #7 plug.
Good luck,
Mike
Moe, I've written several posts in the past warning people not to try the E-head + C-body HP manifold combo because of #7 plug interference.
If you really want to try to make the HP manifolds work, here's my advice:
Don't bother looking for the Accel shorty plugs. They won't help. They're not much shorter than the recommended Champion plugs and won't move the boot far enough away from the manifold downpipe to make a difference.
I am using a hi-temp tight 90* boot and my #7 plug wire loops up from the back of the engine and along the edge of the valve cover/intake manifold to get to the distributor. (That is the factory wire routing for my 66, I don't know if they changed it for 67.) I also use a Moroso woven ceramic boot protector. These have the highest temp rating available. They are Moroso #71990 but I think they may have been discontinued. (The material was actually developed by 3M and is still available from 3M.) Even with these boot protectors, I still have to replace the #7 plug boot at least once a year.
I'm using a Mopar orange box ignition. If I was using a higher-power ignition system like an MSD, it would probably arc through the boot and protector to the manifold within minutes of startup when at idle. That's what happened when my engine was on the dyno, and they tried fibreglass insulation to protect the boot.
Also, for servicing the #7 plug, I cut-down a regular spark plug socket really short so I could slip it onto the spark plug. I ground a new hex into the outside of the socket so I could turn it with an open-end wrench. A standard spark plug socket will hit the manifold, cock sideways and snap the spark plug insulator more ofthen than not when removing or installing the plug. Obviously, you must jack-up the car and climb underneath to service #7 plug.
Good luck,
Mike
