Just a guess, but I think it's 1/0. Either that or 2 gauge.

 

I thuink Mechanos is right for the slugs. I've never used them, but I'm sure a call to Del will clear it up. I've found them quite easy to deal with.

I'd also get some of the super-duper heat shrink available through Del, to cover things up when you're done.

It is important to note...that solder is not POURED into an existing joint. Both things to be joined must reach temperature for solder to FLOW...then the solder flows into a joint. Temp is reached when the parts will melt the solder without help from the torch (at least a little) When temp is reached it will flow, and through capillary action coat everything that meets two criteria 1) proper temp and 2) solderable material (brass, copper, tin).

Propane torch with proper tip should work grand.

I'd guess the solder slugs also have a flux built into them. Bar solder has no flux so seperate flux is required. Wire solder may or may not have flux...it will say flux cored if it does have flux. Flux is required to keep the metals from oxidizing as you heat them. the flux also helps control where the solders flows to. If upon heating, it flows all over your connector...expect a solder coated connector when you're done...LOL

Call Del.

I'm not sure of the wire size...but I'd suspect 1/0 or 2/0. Gotta be bigger than #2.

If the factory lugs are crimped on..there is no way of salvaging of the wire where it engages the factory lug that I can think of. Make sure you can live with a bit shorter wire. I don't think the Dodge's were too bad for this. My old Ford was .