RockAuto.com sells this ACDELCO ground strap for the SC400 for only $5.70:

Part # 6ST14 CABLE,BAT NEG {#88860131}
**Non-stock item--shipping delayed up to 12 business days**

That's a great price, but would there be any advantage to getting an OEM cable?

As for running ground cable to other parts of the SC400, some specifics or pics would be helpful.

 

A ground cable is a ground cable-- is a ground cable......" " " " " '

I described a really good way to do it in a previous post--

Single distribution block on firewall or on strut tower/s, then strap the back of each head to the grounding block/dist. block-- then the intake manifold, then the block/ trans---

Then ground the dist block to one or both strut towers-- just loosen one of the strut mount bolts and use that point after scraping any paint off the contact surface...

You don't have to get a fancy distribution block -- a standard electrical grade block from Lowes will work--

Yes it's overkill, but it will restore conductivity back to 100% + of what it was from the factory....

By the way PerryinLA-- check out my car audio page.. It's got a writeup of my latest install--