Using carbon HT leads with acorn caps...

[Bob Culver]

Cross firing from induction is more a problem with V8s where other cyls are within firing range of tdc. As I have recounted before in the 1960s I used to give a colleague a lift from our hometown on Sunady evenings. Although no definite pick up time he was always waiting outside the front door...saw me coming on the TV! Some claim the carbon in other later distributors was resistive giving some suppression. The pri side of unsuppressed ign on an oscilloscope is a bewidering mess. 
The manual advance cars are prone to leads coming loose at either end.

[A G Wood]

Hi

Re the bundling of leads together, the rubber rings are as per Austin factory photos from the 1920's and 1930's.  They lend extra support to the wires, and I have had no problems with misfiring.

I have seen 6 cylinder engines where the factory plug leads are run alongside each other in conduit, with apparently no ill effects.  Presumably the insulation must be up to scratch.

For instance:
   


And a lot of US cars took a lot of care to conceal their 8-cylinder HT leads (particularly Buick 248/320 inline 8s) inside sheet metal conduits as it was apparently the fashion of the day to do so.

I recall fitting new H.T.leads to engines back in the seventies . We had a Lucas fitting box full of the different types of ends, Split washers, countersunk woodscrews, copper pins in an uneven "u" form. Straight and angled push on ends for plugs and distributor cap. Threaded coil and dizzy cap acorns, Inline and plug cap suppressers
, spare distributor carbon brushes and springs. I/d love that box now, but I expect  like a lot of kit, binned by an enthusiastic parts manager.

Yeah, same here. And the 'breakdown box' filled with capacitors, ballast resistors, contact breakers, caps, rotors etc.