Michael, if I were you I'd cut off the 5/8 threaded rack mounting bungs that I welded on and build some mustang II style rack mount's you could keep this manual rack.I will find a photo and post up. Welders series co. builds some.These are $8.00 dollars each and will fix your problems.
http://www.welderseries.com/blog/?s=must+II+rack+mount