I went with the original mount repaired with the $12 Prothane bushing. Yours looks like heaver gauge steel too.
I can use more height, because when I changed to the longer 727 AT. the drive shaft angle changed. I stacked two 1/4" stock spacers between the mount for a correction to upward 1.3 degree, but it's still not a downward angle to the drive shaft. The other thing I did was to swap out the SS springs for the Mopar 440/cuda type and that lowered the body and also changed the front u-joint angle. I've seen NHRA stock racer's drive angles and they looked like mine now. I asked the owner about the front angle and he said that it straightens out when the power is on because the front raises the whole car.
The rear pinion angle at rest, is 4 degrees nose down, compared to the drive shaft, the actual degree @ the housing pad to pinion is 5 degree nose up when pads are level (factory welded, stock pads, 1968, 8 3/4", B body housing using Dr. Diff. front hangars in the bottom hole). Also, the shaft still runs vibration free.
I'm gonna try one of those complete Prothane transmounts , for the increased strength it offers. thanks!