Gear Vendors uses the Laycock overdrive that was used behind Jaguar, Triumph, Volvo, and several other European cars. It has no resemblance whatsoever to the B-W overdrive unit. Good item, but horrendously overpriced! I'm getting set up to add a Laycock unit to my 85 Ford E350 mini-motorhome behind a 460 V8 with a C-6 3 speed. It will be a divorced unit mounted on crossmembers between the main transmission and the rear axle like a transfer case.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!