I replaced the leads in mine although it is not supercharged. Getting the leads to the far cylinder bank was a bitch of a job. The originals were in a plastic tube and had a locater clip although due to the lack of space I went without for the replacements. I had to loosen the alternator and lift it to pass the leads through as it was.
Does anyone know the purpose of the aluminium shrouds on the original leads? The Bosch aftermarkets do not have them, although do not seem to affect performance.
The Aluminium Shrouds are Heat Shields, and are supposed to protect the Rubber ends from perishing/Drying out.
Best to leave them on. It also makes it easier to pull the leads off the plugs and puts less strain on the leads.
Repalced a set on my old VT once, never again, had to unbolt alt and top engine cover, I put on a set of Top Gun leads they worked fine and as oztech007 said leave the shrouds on.
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