Renault 25 or similar transaxle was once a popular option and adaptor plates were available for all sorts of engines. Not sure what you'll find these days as I'm going back 20 years or more. The Audi transaxles from A4's and A6's could be a modern option, they are plenty strong enough for a Ford V6.
Rather than mess with adaptors it might be easiest to go buy a complete and on the road Audi with a V6 for a few hundred quid and swop the lot across into your chassis ?
Last edited by Lucky@LeMans; 9th September 2019 at 17:24..