Author Topic: Big block ignition lead lengths  (Read 5051 times)

My68SS

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Big block ignition lead lengths
« on: July 11, 2010, 03:24:54 PM »
Hi crew, does anyone know what lengths the factory ignition leads are for bb?
A couple of pics showing correct routing would be great too, if anyone can help.

TIA  :)
Rob
1968 12C SS
L34/M40
12 bolt posi 3.55

JohnZ

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Re: Big block ignition lead lengths
« Reply #1 on: July 11, 2010, 04:47:26 PM »
The routings are shown in your Assembly Manual, in section L35, sheet A6.
'69 Z/28
Fathom Green
CRG

My68SS

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Re: Big block ignition lead lengths
« Reply #2 on: July 12, 2010, 09:47:28 AM »
Cheers John, [why didn't I think of that!  ::)  :) ]
Is a right angle boot for No 7 plug correct, with all other plug boots just slightly angled?
Also, the AIM shows the lead for No 5 in the front most rocker cover retainer slot, then 1, 3 and 7 in the next slots. This routing of No 5 seems a little messy and unnecessary?
Is this how they were arranged from the assembly line?
Rob
1968 12C SS
L34/M40
12 bolt posi 3.55

JohnZ

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Re: Big block ignition lead lengths
« Reply #3 on: July 12, 2010, 03:13:23 PM »
Maybe a '68 BB guy will chime in - I'm not that familiar with the BB details (Z/28 guy here).  :)
'69 Z/28
Fathom Green
CRG

big iron

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Re: Big block ignition lead lengths
« Reply #4 on: July 12, 2010, 09:10:07 PM »
Rob,
All spark plug ends were the same.
Look at the firing order of the L35 18436 57 2. The 5 and 7 wires were separated to keep the number 5 wire from ( cross-firing) inducing an unwanted spark in the number 7 plug. This can lead to detonation, preignition and broken parts.
Bob

My68SS

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Re: Big block ignition lead lengths
« Reply #5 on: July 13, 2010, 01:20:56 AM »
Hi Bob, your right! 7 will be half way through it's compression stroke which creates a danger of any ignition leakage from 5.
How solid are you on all boots being the same? The reason I query is that windy city muscle on ebay is selling repro lead sets in which No 7 is a right angle boot.
I have to admit though, a right angle boot doesn't ring right or seemingly offer any advantage.
Also, whilst the AIM is only pictorial, it doesn't indicate any difference with No 7's boot
Rob
1968 12C SS
L34/M40
12 bolt posi 3.55

big iron

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Re: Big block ignition lead lengths
« Reply #6 on: July 13, 2010, 03:51:49 AM »
Ron,
Not as solid as I thought.
You got me thinking so I checked a set of Packard TVR wires that I have for a L78 I am building and sure enough you are correct, #7 has a 90 degree boot.
The only reason I can see  for the 90 degree boot is so the wire does not rub on the booster.
I have never been a big fan of TVR wires as they do not work well with heat and CD systems.
I hope I did not lead you too far astray.
Bob

My68SS

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Re: Big block ignition lead lengths
« Reply #7 on: July 13, 2010, 09:01:21 AM »
Ah of course, the booster. Mine is on the right side [Aussie], yours will be on the wrong side.... [kidding!!  :D]
Is the boot on your No 7 lead a grey color like the others, or is it a darker color?
Rob
1968 12C SS
L34/M40
12 bolt posi 3.55

big iron

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Re: Big block ignition lead lengths
« Reply #8 on: July 13, 2010, 01:17:19 PM »
Rob,
You mean that there were Camaros made that have the booster on the right side?
The boot on the # 7 wire is black, just like the wire.
Remember when you order your wires, get the correct date code.
Bob

My68SS

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Re: Big block ignition lead lengths
« Reply #9 on: July 13, 2010, 03:17:36 PM »
I was being a bit 'tongue in cheek' with a play on words there  :)
This car was an XCO to Sydney, Australia and was converted by Bill Buckle Autos in Sydney to RHD, hence 'right' [correct] side for me.

Seems like windy city muscle has got it totally correct with a right angle boot for No 7 and in black.
Reading through his description for battery leads, he seems to be pretty fastidious about getting things as correct as possible.
Rob
1968 12C SS
L34/M40
12 bolt posi 3.55