6010 is the right call for a cherocar.
all and all Not talking body sheet metal
I personally use a lot of flux core (fcaw) for a few reason. .035 110v and 100ft of extension cord is very doable. hard wire you should be running 220v for structural pieces. cant remember tomany rents that have 220v aside from the dryer and stove. extension core for 220v are $$$$. . Less prep, a wire wheel in most case is all that needed due to the flux. Were hard wire needs bright shinny metal. Which can be hours or work. Paint, road grim, oil, undercoat and the Lovely factory zinc anti corsion plating.
Better penetration (again not a good idea with any thing grater the 16g) hard wire does not penetrate till you get high enough volt to "spray"
You don't have to worry as much about gas. Yes, around 10 plus mph you can loss gas coverage. With the lack of shielding gas, no worries of leaks. Having Extra bottles on hand, leads are lighter.
Down sides are clean up. Personally a 4-1/2 with a wire wheel or cup and a die grinder with a cup. A little acetone and your ready for paint.
With the PNW being so wet, one need to remember the flux in the wire can absorb moisture. Which can and will low tensel strength(cracking) and or porosity. Bagging your wire (hard or flux) is always a good idea
Like anything. You need to know what your doing. I've seen a few rigs build with SMAW over the years. ( phucking pipe/steam fitters)
