[CMars45000]

If you want a clutch-style Posi, Eaton was the original supplier and is basically identical nowadays save for the clutch material (now that are carbon instead of what I am sure was some type of asbestos-containing stuff, back in the day). Plenty strong, but does need a friction modifier. Very streetable, soft engagement.

Detroit TrueTrac is a bit more aggressive, no wearable parts, no friction modifier, stout as heck.

That being said, I put an Eaton in mine when I rebuilt it. Can't go wrong either way, but having driven both, I prefer the more tame street manners of the Eaton.