AMI D40 78 to 45 conversion

I'm considering converting a D40 from 78's to 45's. If this is possible, is there a good source for conversion kits and a guide/book on doing this.
thanks,

Kirk

Kirk - I'm looking to convert an AMI B back to 78's from 45's.Maybe we can trade the parts? Same model 500 mech. I need the original shorter S-shaped tone arm and the 78 cam. I also have the 45 drive bushing that goes on the motor. Let's talk. Carl.