I've done it, used the stock wiring, very easy swap, and has worked great

probably gonna upgrade to 4gauge anyways though next season

 

I've swapped in a 3G and intended to replace the stock cable, but never did. I'm waiting until I install my Mark8 fan before I redo all the wiring, and properly at that.

 

If you trace the double wires backwards about 8-10" you'll find they go into a single wire, mine is cut there and a new section soldered in which has worked perfect for the last 3 years, even will all acc's on the wire does not get hot. Same results with the several others I've done the same way.

Rick