what gauge of wires?

Rapid Robert said
I used welding cables from the battery to the main cutoff switch & the same from the cutoff down to the starter. Overkill I'm sure but the battery is behind the drivers seat & I had the cables left over from the last car that wrecked. I'm useing at least the OE gauge wires everywhere & 10 gauge from the alt to the cutoff switch. I crimped the wires as hard as I could but useing parts house taiwan blue & yellow connectors which are cheap/poor quality. Today I went to solder them in addition to the crimping but my very small soldering iron could not get hot enough. I can get a larger iron or am I go to go as is?

What exactly are you attempting to solder with an iron that is too small? If it's the cheap blue and yellow connectors, a small iron would easily be sufficient but you'd want to remove the plastic insulation on them and then use your own heat shrink.

If you're trying to solder battery connectors, you'll have better luck using a torch. When using a torch to solder a metal connector, hold the torch to the connector until you see a dull color drift across the connector. At that point the connector is ready for solder.