Motor ruling question

[Richard Kensicki <richk@sparta-junction.com>]

A number of classes allow motor swapping but it has to be the same
brand, Ford -> Ford etc. With all the aftermarket pieces including
blocks and heads is there some general cut off rule as to when its no
longer a "brand" motor. This seems to get a bit gray when you compare an
Arias engine with say a Chevy. Of course it would make a good debate
when you start comparing high performance pieces that are produced by
all the major car companies. Has this ever been a concern?

Rich