RE: What's the difference here?
Kweasel,
Good call!!
There are a few manufacturers that like to list the engine weights of some of heir products less ignition, spark plug, and the prop washer and nut. The word is not to take weight listings too seriously.
As`far as the BT-32 is concerned, one could go a little larger, quite a bit better, a little lighter, for a little less. Keep shopping.