Steel mtb frame with alu rear suspension fork?

Hey Folks,

I am wondering wether there are builders here that have modified a steel mtb frame by adding a alu rear suspesion fork from a alu full suspension donor bike.

I was thinking about it because i came along a free alu full suspension bike and wish it was a free full suspension steel bike. (what i could only find in my dreams) I like steel bikes.

Anyone has done that? Pro's - Con's?