After exhausting research, not much to be found. Before I put the Nailhead/ST400 in my 40 Buick, I would like to upgrade the steering box to a Saginaw/Borgeson 525 manual box. Nobody seems to make a bracket, so I guess I need to roll my own. The chassis is different from the Chevy, but Olds, Poncho, and Buick are very similar from 40 to 47. Anybody out there done this and can share a pattern for the bracket? I want to keep the original chassis and front suspension as those cars rode well, and a dropped spindle kit is available as well as brake upgrades. I know a Buick is off the beaten path and as @squirrel puts it is a grandpa car (I resemble that comment), but it is something different. Anybody?
Wasn’t the 525 used in some GM pick ups. Uses the same bracket mount as Vega. Shouldn’t be that big of issue.
I could be wrong but I think the 525 and Vega have the same 3 mounting holes. Lots of Vega stuff out there.
If you didn't want to start from scratch; you could pick up a Weedetr or Pete & Jakes '35-'40 Ford mount and trim off the "Ford" flanges and you would be half way to a mount.