Auto engine conversions fpr aircraft have been around since the first combustion engines were available.
Minimizing failures means 'doing it right' .. you cannot just bolt it in and expect an auto engine to perform well inverted ..an such
If anything ..these days are a golden age for conversions.
A properly thought out design and a CnC machine can solve any problem areas.
Heck a good machinist can build his own motor from blocks of suitable material.
As for the LS series motors . . you would have to go some to find a better engine.
They are anvils ..just amazing all the way through.
-Frank aka GE