Your original 14" wheels have less than the minimum 3-1/2" Back Spacing but there is NO Inboard Safety Hump to accommodate a caliper11" because drums simply didn't need the hump.. This hump appeared with Granada/Versailles/Mustang disk brakes. - Dave[/quote]
I realize that the presents of the safety hump in the rim may aid in the fitment of the disc brake caliper, but, I felt one should maybe clarify the fact that the "Safety Hump" was not instituted for that purpose (note that it is present on both ends of the barrel). I believe rather to provide increased retention of the tire bead, under the adverse conditions of low inflation pressure values and high sidewall loads, such as in cornering; as even momentary disruption of the seal between rim and tire bead may cause deflation in a tubeless tire.
Also, it is advisable to avoid using wheel spacers for the purpose of making the improper fitment work for a number of reasons (new tread?). Scott.