Curious spark plug wire routing

[Michael J.]

I have just replaced the non-original spark plug wires on my '66 L79 with dated correct replacements and found the routing of the front two plugs on each side of the engine to be very odd. The wires were routed through the motor mounts, so tight that the boot and metal contact would not fit through it to get it out and I had to cut it off to get the old wires out. Needless to say I could not route the new wires that way. This must be a "Bubba" installation, right? Surely this couldn't have been a factory type routing routine, or could it? It looked like the wires were routed through here before the engine was installed on the mounts, the only way to get the wires through with the molded boots on them. Thanks for any ideas.

[Ken A.]

Re: Curious spark plug wire routing

Bubba was the engineer who routed all small block wires in the early days. Your wires were routed correctly.

[William C.]

Re: Curious spark plug wire routing

undo the mounts, jack up the engine, unbolt the mounts, and the wires go right thru. The St Louis plant had options that are less evident once the engine is in the car (BTW all chevy pass cars were routed similarly.)

[Jim W.]

Re: Curious spark plug wire routing

undo the mounts, jack up the engine, unbolt the mounts, and the wires go right thru. The St Louis plant had options that are less evident once the engine is in the car (BTW all chevy pass cars were routed similarly.)

As strange as this looks once your under there, mine were routed the exact same way. The only way to replace them is the lift the engine on the one side, slide the wires through the motor mount and the gently lower the engine back down taking care to not pinch the new wires, You can do it yourself with a block of wood and letting it back down slowly so you can keep pushing and pulling the wires to make sure their not getting pinched. Good luck !

[Duke W.]

Re: Curious spark plug wire routing

There are a couple of ways around this. With some care, a suitable tool, and a little silicone spray lube, you can remove the boots from either end of the wire.

IIRC the last time I did mine a long time ago, I removed the distributor boots and routed the wires from the plug end, and I don't recall having to do anything with the engine mounts.

Duke

[John H.]

Re: Curious spark plug wire routing

IIRC the last time I did mine a long time ago, I removed the distributor boots and routed the wires from the plug end, and I don't recall having to do anything with the engine mounts.

Duke

Yup, removing the distributor boots works that way for the front four wires.

At St. Louis, the front four wires were installed before attaching the engine-side mounts - no routing problems.

[Larry M.]

Re: Curious spark plug wire routing

There are a couple of ways around this. With some care, a suitable tool, and a little silicone spray lube, you can remove the boots from either end of the wire.

IIRC the last time I did mine a long time ago, I removed the distributor boots and routed the wires from the plug end, and I don't recall having to do anything with the engine mounts.

Duke

Agree. That is how I did my replacements. No real issues.

Larry

[Mark S.]

Re: Curious spark plug wire routing

I attached a string to the old wire before I removed it. When I removed the old wire it pulled the string thru the motor mount. Then I attached the string to the new wire and gingerly pulled the wire thru using the string to pull it. It took some time, but it worked well.

[Gerard F.]

Re: Curious spark plug wire routing

Michael,

I did it like Mark on my 67 S/B

You have to take the distributor boots off the old ones, or cut them. Tape a stout string or #12 or #10 wire taped to the end and pull it through from the plug end.

Then attach the new plug wire (with the distributor boots removed) to the string or wire and pull it through from the plug to the distributor.

It is best to work from the underside of the car or from a pit. I have somewhat of a pit in my garage with removable wood planks in the floor and a storage room below. But it still ain't easy for the front 4 wires.

Make sure you mark each new wire for the plug position at both ends, or do them one at a time. There is a little brace under the lower ignition shield with notches in it for the plug wires. If you can thread through that brace you won't have to remove the lower ignition shield. You can see it from the underside. I was able to thread it through without removing the lower ignition shields.

But, it is not a piece of cake job. If your kids or grandkids are around, refrain from using expletives. Otherwise have at it.

[Michael J.]

Re: Curious spark plug wire routing

DOH!!! I should have known some engineer at GM thought that routing up. Thanks for all the tips guys. But at the end of the day I just punted and ran the new wires beside the motor mounts around to the front two cylinders on each side. The wire looms attached to the oil pan bolts help keep them off the hot parts of the engine pretty well, and luckily the judges don't look down there. I have to admit taking all the ignition shielding off was a pain, especially since I have A/C, that right side is a PITA. But, all done now so new, proper dated wires, and a new correct, numbered cap and coil. Getting closer for thr regional in Oct.