I have a 1986 Buick Regal Limited, motor swapped to a Buick 462 with long tube headers. I'm exploring the option of trunk mounting my battery. I have a decent understanding of the concept for wiring & making it safe. I'm looking to get opinions on how to route the battery cables from the engine compartment to the trunk. I was thinking of running them through the frame where fuel lines would normally run down the passenger side. Around the inside spring pocket (but clear of spring) & out the oval hole on engine crossmember (I did similar with fuel lines on DS). Can a junction point be mounted near factory battery location, then a 2nd wire to positive terminal on starter (through factory straps along bottom on engine block) ? *Trying to only have positive battery cable & purple solenoid wire down on starter. Also is there any issue with using SS rubber insulated P clamps to support cables where they are routed ?
Everything you mentioned will work but also remember that every junction point can become a spot for resistance at some point. My last trunk mounted battery I ran the battery cable inside the car down the tunnel just inboard of the seats and out the floor through a grommet straight to the positive starter post. Ran the purple wire right alongside it with no issues. I kept all of my primary power wires inside the car that way including the main feed to the fuse box. I used a one-wire alternator with #8 wire also to the positive starter post and it charged the battery through that pretty well. Ran the car that way several years without a single electrical hiccup. Also if you want to run it on the frame the adell clamps work just fine.
I did a battery relocate to the trunk and routed all the wire the same way, inside the cabin. Makes me feel more secure knowing that the big wire is protected.
