Topics are all over the place...

Its very simple. The 4.6IS came with 3.91 ratio diffs. Most other BMWs have a 3.6X ratio, including the models that came with a manual transmission. So your manual transmission likely came from something with 3.6-something ratios.

Fortunately, the 4.4i came with 3.62 or 3.64 (can't remember which). Swap those in and you'll be more appropriately geared.