might just run the oems then and see how it goes worst case I send the supercharger out.
the internals are fine with a upper pulley on pump gas it isn't going to damage this engine unless very intentionally tuned to do so and guys like HHP, Dusterhoff etc have done god knows how many of these stage 1 setups without issue. People run way more radical setups than me on the stock internals and are perfectly fine and if I was messing with the internals id just make it a 426 and put a bigger supercharger on it.Have to mention you are worried about the supercharger bearings from adding an overdrive pulley. This is a valid concern. But you express no concern for any of the engine internals from the risk they run from being exposed to more HP.
If you think the supercharger bearings need upgrading what about the engine internals?