I would use mechanical fittings. I use Norsemen on all of my lower fittings. I use swag fittings on most of the tops of my wires because money is always an issue. The reasoning is that water will not, or at least should not, travel up the wire and cause rust. Areas where the the water could run down the wire into the swag is where I use mechanical connections. If I was to go with all mechanical connections at once then I would need an additional 12 at about 75 bucks a pop. That's about another 900 to 1000 dollars and that's starting to look like real money. If all you are doing is a back stay insulator then I would spend the money for mechanical. You can do what I do and change to mechanical when you get the chance. Sort of sneak up on the cost one or two at a time. Actually, I have 8 left to go.