I'm not sure about the amp ratings off the top of my head. There are different sizes available and some accommodate larger wires so if you're looking into it I'm sure you can find something suitable. The fuel pump is run off a relay but it's probably 15-20A? I used 14ga contacts for that wire. Most of the time you'd use 16ga for that series of connector. The contacts with the green stripe can be used safely with larger wire but still fit the smaller connector cavity. The level sender current is minimal. For my electric fan and water pump I am using Metripack 630 which can accommodate up to 10ga wire.
