A friend of mine had one of these Gear Vendor units in his '66 Impala SS with later 454 ci engine. He loved the Gear Vendor.
Got a line on a 2.78 (thanks Chris). Pics attached. Looks pretty good to me, but gear guys chime in….whadaya think? (besides the fact that overdrive is the solution and I’m just adding a make work before I decide to call Monster).
Why would you call monster? Depending on the trans you want, there are builders who specialize in BOP/Buick.
First name that came to mind. Yup, if I go that way I'll reach out here for some recommendations. So far this is far and away the best info form I've come across, regardless of topic.