A puzzle solved!

[antijam]

When I bought my '71 350 it had a few running issues so as a first response I cleaned the points and fitted a new distributor cap, spark plugs and plug leads. The leads were specific to the car but when fitted seemed unnecessarily long. The car was fitted with headers and the leads routed along the sides of the rocker covers and down to the plugs......

This seemed logical enough but there was a lot of spare plug lead to be tucked out of the way.

I'm currently sorting an intermittent starting problem and to remove the starter motor the header has to be removed first. With both off I noticed an odd 'hockey stick' shaped piece of tinwork attached to the side of the block.....

I couldn't fathom its purpose until an internet search revealed it to be heat shield ducting for the HT leads. Ahhhh! (light bulb moment) the leads were originally intended to run down the side of the block, inside this heat shielding and come up underneath the plugs rather than from above, this longer route necessitating longer leads. Puzzle solved!

Whether it's worth re-routing my leads as original I'm not sure. With the leads under the heat shielding and the headers fitted, replacing them in the future may be a major job. It may be more sensible to stick with the present run but shorten the leads. Many online pictures of sbc installations show the leads running alongside the rocker covers. What routing does anyone else with headers fitted take, down from above or up from below?

 

[Oneball]

There’s two different sets of leads for SBC. Over the header and under the header. I’ve got over.

 

[Mad4slalom]

When I bought my '71 350 it had a few running issues so as a first response I cleaned the points and fitted a new distributor cap, spark plugs and plug leads. The leads were specific to the car but when fitted seemed unnecessarily long. The car was fitted with headers and the leads routed along the sides of the rocker covers and down to the plugs......
View attachment 12108
This seemed logical enough but there was a lot of spare plug lead to be tucked out of the way.

I'm currently sorting an intermittent starting problem and to remove the starter motor the header has to be removed first. With both off I noticed an odd 'hockey stick' shaped piece of tinwork attached to the side of the block.....
View attachment 12109
I couldn't fathom its purpose until an internet search revealed it to be heat shield ducting for the HT leads. Ahhhh! (light bulb moment) the leads were originally intended to run down the side of the block, inside this heat shielding and come up underneath the plugs rather than from above, this longer route necessitating longer leads. Puzzle solved!

Whether it's worth re-routing my leads as original I'm not sure. With the leads under the heat shielding and the headers fitted, replacing them in the future may be a major job. It may be more sensible to stick with the present run but shorten the leads. Many online pictures of sbc installations show the leads running alongside the rocker covers. What routing does anyone else with headers fitted take, down from above or up from below?

I remember the po in the usa of my 72 telling me that a plug lead change takes 6 hours and thats him and used to it

 

[Roscobbc]

Might be a good idea to rip out that tatty header wrap. It can hold moisure during extend non-use periods and rot-out the header tubes.

 

[Nassau65]

Might be a good idea to rip out that tatty header wrap. It can hold moisure during extend non-use periods and rot-out the header tubes.

Plus it looks bloody horrible.

 

[antijam]

Might be a good idea to rip out that tatty header wrap. It can hold moisture during extend non-use periods and rot-out the header tubes.

A very good idea Rosco - it's on the list. I'm working on the other side at the moment sorting starter motor problems and have already refurb'ed the header on that side....

Before...


...and after


When that's back together I'll tackle the other one.

(and you're right Nassau65 - it does look bloody horrible)

 

[Nassau65]

Wow, that looks so much better.

 

[antijam]

I remember the po in the usa of my 72 telling me that a plug lead change takes 6 hours and thats him and used to it

If that's the original lead run I can well believe it! Changing the plug leads with headers on with the 'up and under' routing looks a formidable challenge. I've decided to stick with the over the header routing with shorter leads; not perhaps as tidy but at least easy to change.

Gotta be one of the things in favour of 'Hemi's.....

 

[Derek Nicol]

Mine..

 

[Mad4slalom]

If that's the original lead run I can well believe it! Changing the plug leads with headers on with the 'up and under' routing looks a formidable challenge. I've decided to stick with the over the header routing with shorter leads; not perhaps as tidy but at least easy to change.

Gotta be one of the things in favour of 'Hemi's.....

View attachment 12125

 

[Roscobbc]

If that's the original lead run I can well believe it! Changing the plug leads with headers on with the 'up and under' routing looks a formidable challenge. I've decided to stick with the over the header routing with shorter leads; not perhaps as tidy but at least easy to change.

Gotta be one of the things in favour of 'Hemi's.....

View attachment 12125

A 'diddy' Hemi!

 

[Roscobbc]

Run mine with the HT leads 'tucked' behind the valve covers, then run parallel level with bottom of valve cover/just above header flange.

 

[teamzr1]

Best any time things are close to high heat such as sparkplug wires is using this for only $16 US
Both of the below handle up to 2,100 F degrees

Spark-Plug Wire Heat Shield Hose - 1/2"ID X 10FT 2500°F Automotive Heat Wire Shield Protectors Boots Hose with 10 PCS 7.8 Inch Stainless Steel Zip Ties for Car & Auto Wire Loom Brake Cable, Titanium​

Amazon.com

If just needing thermal protection near the boot wire to sparkplug
Use these short ones for under $20 and comes in different colors

Amazon.com

I use the short ones as having headers, and they are 20 years old and still look fine

 

[CaptainK]

I have some of those spark plug socks. Not fitted them though because I have 90 degree plugs on my leads, and can't get the things over the plug ends. Yes I could unwire the plugs, but I'll probably break them. Its on my to-do list, but to be honest I keep forgetting I've got these socks until someone reminds me like you just did, or I randomly find them again in my garage.

 

[antijam]

I have some of those spark plug socks. Not fitted them though because I have 90 degree plugs on my leads, and can't get the things over the plug ends. Yes I could unwire the plugs, but I'll probably break them. Its on my to-do list, but to be honest I keep forgetting I've got these socks until someone reminds me like you just did, or I randomly find them again in my garage.

Some socks are more generous than others. I too have 90° lead plugs but after routing the leads down to the headers with Moroso clips these socks have enough room to fit over the wire and round over the cap and spark plug. With headers the leads and their caps are very close to hot metal and these socks do help to keep them from getting 'cooked'.

 

[Chuffer]

Best any time things are close to high heat such as sparkplug wires is using this for only $16 US
Both of the below handle up to 2,100 F degrees

Spark-Plug Wire Heat Shield Hose - 1/2"ID X 10FT 2500°F Automotive Heat Wire Shield Protectors Boots Hose with 10 PCS 7.8 Inch Stainless Steel Zip Ties for Car & Auto Wire Loom Brake Cable, Titanium​

Amazon.com

If just needing thermal protection near the boot wire to spark
Use these short ones for under $20 and comes in different colors

Amazon.com

I use the short ones as having headers, and they are 20 years old and still look fine

I fitted them to my C3 about three years ago as my HT lead and Dizzie installation is non standard . They were a good investment for protecting the leads.

 

[CaptainK]

Some socks are more generous than others. I too have 90° lead plugs but after routing the leads down to the headers with Moroso clips these socks have enough room to fit over the wire and round over the cap and spark plug. With headers the leads and their caps are very close to hot metal and these socks do help to keep them from getting 'cooked'.

Sadly I can't get my socks on from either end. Pulled the plug lead from spark plug end, and also from distributor end (both 90 degree ends), but can't get the sock over either end annoyingly. Been thinking of taking the plug caps about, but concerned I might ruin them.

I also have a set of those wire holders similar to yours - another one of those things I forgot I ordered a few years back but haven't fitted yet.

 

[teamzr1]

These heat socks or long lengths are sold with diameters of 1/2, 3/4 and 1 inch
to fit the needs of type of boots, the sparkplug wires are

If the diameter is a bit too large than also get metal zip-ties that work well in high heat that
allows end of socks to have a better looking fit.