Small bolt pattern 15x9 wheels

I'm building a '68 Barracuda for racing. The rear is an 8 3/4 with the small bolt pattern. There is a home built 15x9 wheel 5inch backspacing with 275/60r15 cooper tires on it. I need a second set of wheels to put my 275/60r15 drag radials on. Of course there are no wheels in the bolt pattern and size I can find. I was told ford wheels may fit. What is everyone running on this combo for a deep wheel? Or am I stuck upgrading the drum brakes. Thanks.