The Fiesta brake conversion is designed to allow for larger, better stopping brakes to fit under 10" or larger wheels.  To do this, 8.4" rotors will need to be turned down to 7.9" (which, if one doesn't have access to a lathe) adds to the cost of this conversion.  The following is an estimate of costs, per Tori Miller:

Custom brake hoses $100 (possibly less) 
Fiesta Calipers $80 (with pads)--> US Spec 1977 to 1979
Metro drive flange (HUB) $100 each, new.
Machine work on making 8.4" rotor down to 7.9" $25

Rotor Size Differences

Hub Comparison

Holes Drilled

Caliper Side-by-Side

Slide Mounted

Slide Mounted- Front

Clearance Problem

Proper Clearance

Proper Clearance- Close-up

Finished Caliper & Hub

Caliper Mounted

Finished and Mounted in Wheel

Conversion Hoses

Brake Hose Bulk Head Fitting

Brake Hose Caliper Ends

Bulkhead Fitting End Inside

Caliper and Hose Finished