As both the 4.4 and 4.6 bellhousings are machined from the same casting, if you’re unable to source a 4.6 bellhousing it may be possible to find a machine shop that would machine down the radial stiffening ribs on your 4.4 bellhousing to provide sufficient clearance for the larger L51 converter. I think this would be a worthwhile upgrade if you get the opportunity to source an L51 converter from somewhere.

https://hosting.photobucket.com/7b75...080&fit=bounds

https://hosting.photobucket.com/7b75...080&fit=bounds

The 1058 000 035 5HP24 model for the 4.8 E39 Alpina B10 & E52 Alpina Roadster also used the larger L51 converter, but these were produced in much smaller numbers than the 4.6is.

Phil

Thanks RRPhil. It does seem like they just eased the ribs back a bit, but other than that it’s the same bellhousing….that should be an easy job for a competent machine shop. Or an incompetent amateur with an angle grinder!

Different stall speeds I think. I wonder if the 4.4 DME and/or transmission controller are smart enough to throw a code(s) if it senses this difference?