Converting from 4" to 4.5" boltpattern

Hi guys!

I have a -64 Valiant with 4.5" boltpattern in the rear and 4" in the front. Was thinking about how I could get the big pattern also in the front? What do I need to acomplish this, and where can I buy the parts?

Is there anyone that sells complete kits?

Would be greatfull for any tips! :)