63Avanti wrote:

On Oct 29, 6:06 pm, wrote:

A significant amount of igniton noise comes from the connection between
the plug and the plug wire, and grounded metal shields over the boots
can help here. There are wire kits with these boots, mostly for German
cars, or they can be made with metal tubing slipped snugly over the
metal bases of the plugs.

now this is interesting,
I remember fabricating for my neighbor's '62 Ford a metal can with
braided shielded wires to cover his distributor and cables out to the
plugs. I no longer knew when he drove out of his driveway by watching
the patterns on my TV (UHF).

Any one know if these boots, if self-fabricated, are essentially a
CYLINDER, grounded by contact with the engine block?

Yes. I made some from conduit that extended about 2" above the plugs.
I found it didn't mater whether or not the tops were covered with
metal, but I applied a bead of silicone RTV to prevent the sharp edges
from cutting through the wire insulation. I slit the bottom of each
tube lengthwise to make it easier to press it easier to press around
the hex part of the plug.