Msd wiring through firewall

Hey everyone! Following up on my post about getting those MSD ignition wires through the firewall. It's one of those jobs that sounds simple but can quickly become a headache if you don't plan ahead. When I was tackling this on my C10 for the LS swap, I learned a few things I wish I'd known upfront. 1. Plan Your Path & Gather Your Tools: First off, planning your routing path is absolutely key. Don't just blindly drill! Spend a good half hour with a flashlight and mirror, both under the dash and in the engine bay, to find the best spot. Look for existing grommets or unused factory holes you can repurpose. This saves you from creating new holes and potentially hitting something critical on the other side. My goal was always a clean look – no cluttered wires! For tools, you'll want a drill with various bit sizes (including a step drill bit), a grommet kit, a utility knife, zip ties, electrical tape, and possibly some wire loom or conduit. 2. Drilling & Protection: If you do need to drill a new hole, measure twice, drill once. Start with a small pilot hole, then gradually increase the size. Remember, you'll need enough space not just for the wires, but also for a proper grommet to protect them from sharp edges and keep water and fumes out. I found that a step drill bit works wonders for creating clean holes in sheet metal, minimizing burrs. Once the hole is made, smooth any rough edges with a file or sandpaper before installing the grommet. This step is crucial for long-term wire integrity. 3. Routing Wires Through the Firewall: When it comes to the actual routing wires through the firewall for the ignition box, protect your wires! Use automotive-grade grommets. These aren't just for sealing; they prevent chafing and short circuits down the line. I always add a bit of dielectric grease around the grommet for extra weather sealing. Also, make sure you leave a little slack on both ends of the wires, especially near connections, to prevent strain from engine vibration or movement. For larger bundles, consider using a bulkhead connector for a professional and easily serviceable pass-through. 4. Securing & Sealing: Securing your wires is equally important. Use zip ties strategically, adhering them to existing wire looms or frame components. You don't want wires dangling or rubbing against hot engine parts. A clean install looks professional and prevents future electrical headaches. Once everything is in place, double-check your seals. You can use RTV silicone sealant around the grommet if you're concerned about water ingress, especially if you're in a wet climate. 5. Final Checks & Troubleshooting: Finally, once everything is routed and secured, do a thorough check. Tug on the wires gently to ensure they're not too tight. Check all connections. Turn on your ignition and ensure everything powers up as expected. If you encounter issues, retrace your steps. Often, it's a loose connection or a wire pinched somewhere. This meticulous approach to routing wires through ensures reliability and safety for your upgraded truck. Happy wrenching and enjoy that powerful LS swap!