Legshield spare wheel carrier fixings

Just a quick one
Can anybody recommend what fixings to use to fit an inside legshield spare wheel carrier to my GP,I'm guessing they need to be longer than original but not sure of length. Thanks in advance.
Can anybody recommend what fixings to use to fit an inside legshield spare wheel carrier to my GP,I'm guessing they need to be longer than original but not sure of length. Thanks in advance.