Although not a bubble-pack solution, one can enhance the strength of the bottom end of a two-bolt block with a little thought and inexpensive parts.Using 7/8" keystock and milling the caps so they are flat on top......The pic speaks for this simple solution. Stronger than after market 2 bolt caps. Either method requires checking and align honing. Thus far the pic represents approx $30 spent for all the caps 1-4 and keystock. Not align honed yet.
I encourage cost effective and logical alternatives.
Sorry for the hijack.....
Regards,
HB2
Dissident