All good info above!
This is a PM I got on another msg board from a guy at Indmar. FWIW- I also run the MR43LTS gapped at 45
----When we use standard plugs, like the MR43LTS, we gap them at .045", when we use platinum plugs in a 5.7L, (AC 41-932) we gap them at .060". According to a crossreference I found on the internet, the Autolite 103 is a standard plug that is supposed to be equivalent to the MR43LTS, I would gap that plug at .045" -----