rs, Glad to hear your Cub arrived in good shape. In recent years I have had a few ARFs arrive with crushed wing ribs and then had to cut the wings open for repairs.
I guess it's always a crap shoot whither your ARF comes intact or partially rekitted in the box. Kit building skills overcome the problem but it's still annoying. Yes, the Magnum 52 laid over 90 degrees with a pitts muffler should be good power. I used to prefer Slimline mufflers over Bisson but Slimline is NLA. What is the muffler bolt spacing on the Magnum?