Imperial and metric

[nexus.1]

Hi,

I have an x6, a x6 squared and an x6 Cubed I need to replace some of the old screws under the chasis of the cars and was going to use stainless one's. Most of the screws are still imperial and I would like to change them to metric so does anyone know if the threads are the same pitch or am I going to end up threading half of the holes?

Thanks all.