Wanted 71 Duster Disc Brake Changeover

I have a 71 Duster with drum brakes and small bolt circle on the front.I want to put disc brakes on the front with the 4.50 B/C..Anybody got any 73 & up A body disc brake stuff that is descent? Don't feel like shelling out the big $$ for the A/M stuff when I know it can be done less expensive.

Also on the rear axles I have a small B/C but want the 4.50 B/C and the flange isn't large enough to drill to 4.5 !!! Have I got to buy A/M axles for this swap? Would like disc brakes on the rear too...

Any advice/help would be appreciated

Thanks,
Leonard