It seems that the engine mount is not symmetrical. No problem there, except that the reinforcing gussets Lancair sold me are identical to each other, and only one fits. Not that big a deal, but it does take time to fabricate one that does fit. The guesset I made looks fine, and, being made of 4130 steel, will certainly be as strong as the Lancair gusset. To accommodate the new reinforcing box, I had to trim the strut bearing blocks. That took a bit of time, but the result is fine.